Science topics: Two Way
Science topic

Two Way - Science topic

Explore the latest questions and answers in Two Way, and find Two Way experts.
Questions related to Two Way
  • asked a question related to Two Way
Question
3 answers
Preferably based on personal real life experiences.
The question can be reformulated in these two ways:
What has been your journey into researching from novice to professional ?
Thank you in advance.
Relevant answer
Answer
If you start writing short pieces that do not need full peer review it gives good experience in dealing with editors and reviewers. They can sometimes be very difficult to work with.
Book chapters are a good start. It is usually easy to find people seeking research collaborators for books. Expertise is more important than a past publication record.
You can of course seek collaborators yourself by post an inquiry on RG for instance. Lots of people do.
  • asked a question related to Two Way
Question
6 answers
Can somebody tell me if the wave-particle duality is caused by the collapse of the wave function?
How can matter behave in two ways, it doesn't make sense. It has to have a single description.
Relevant answer
Answer
This is a deeply important question, and it lies at the heart of what my work — Quantum Wavefront Dynamics (QWD) — was created to address.
The short answer is:
No, wave-particle duality is not caused by wavefunction collapse.
Collapse is not what creates the duality — it’s what destroys the wave-like behavior and reveals the particle outcome.
But the mystery goes deeper:
How can one entity behave like both a wave and a particle, and when does it become one or the other?
According to QWD:
• The quantum entity (photon, electron, etc.) is always a real, extended wave — not a probabilistic ghost.
• This wave has a geometric structure — a wavefront — that propagates deterministically.
• When no external disturbance occurs, this wave evolves coherently and produces interference patterns.
• However, when the environment (observer, device, material) interacts with it asymmetrically, it begins to distort the wavefront curvature.
• This distortion leads to gradual localization — the wavefront bends, concentrates, and behaves as if it “collapses” into a particle detection.
QWD’s Key Contribution:
• It provides a single physical description — not duality, not collapse postulates.
• Wave and particle are two stages of one evolving wavefront under different physical conditions.
• Collapse is not instantaneous. It’s a continuous, deterministic, geometry-driven process.
This model aligns with modern experimental findings (like decoherence and interference decay) but removes the need for mystery, randomness, or parallel realities.
If this resonates with you, I invite you — and all reading — to explore my published manuscript:
Quantum Wavefront Dynamics (QWD): A Deterministic Framework for the Wave-to-Particle Transition
Available here on ResearchGate: [Insert Your RG DOI Link]
It presents a full theoretical explanation, simulations, and proposed experimental tests — and offers a unified view that dissolves the duality paradox.
Sincerely,
Adam Dakhil Nasser Alzerkany
Author of QWD
  • asked a question related to Two Way
Question
1 answer
I want to test if the concentration of metals in some birds were influenced by age, sex or tissue. I had to run two separate models of two-way PERMANOVA, one for age x tissue and another for sex x tissue, because I didn't know the sex for young individuals. I had significant results for the factors and its interactions.
However, the software I'm using has no post-hoc test for two-way PERMANOVA.
In that case, is it "correct" if I run a series of one-way PERMANOVA's to test the interactions pairwaise, after the two-way PERMANOVA?
Relevant answer
Answer
Yes, you can run one-way PERMANOVAs as post-hoc tests if properly corrected for multiple comparisons. Consider pairwise PERMANOVA (if available) for a more direct approach. Check assumptions (e.g., dispersion homogeneity via PERMDISP) to ensure significant results are due to mean differences, not variance differences.
  • asked a question related to Two Way
Question
1 answer
I want to do the following topic for my PhD thesis:
"Presenting a retention marketing strategy with a customer reputation approach using data mining"
Given that the research method is qualitative, I request you to answer one of the following questions in one sentence.
Is it important to you that the bank has a system for engaging with lapsed customers?
Is it important to you that the bank tries to have a two-way interaction with customers?
Is it important to you that the bank tries to build long-term relationships with customers?
Relevant answer
Answer
The answer to all three questions is positive.
The second and third questions are related. Which foregrounds the perspective of direct marketing... Since it is very important that the customer trusts the bank, this is also true in the case of the bank.
The questions and the answers given can also be examined from a cause-and-effect perspective.
Regards,
Laszlo
  • asked a question related to Two Way
Question
51 answers
In the following paper;
considering
a) the experimentally verified two-way SOL = c to very high accuracy [1],[2],[3],[4]
finding the light times in a configuration of train and embankment with
b) the experimentally verified twin effect, to second order approx in v/c [6],[7],[8],
c) the Sagnac effect, verified to first order approximation in v/c [5]
the result is that the SOL in the embankment is L/c
while the SOL in the train is gamma*L/c, at variance with a)
Since a) must be complied, the Sagnac effect in longitudinal motion, an experimental evidence with a lower accuracy must be ameneded by assuming the Length contraction of the train as REAL.
THis means that Length contraction cannot be niether reciprocal nor symmetrical. That involves the existance of a preferred frame in which it is clear what is the non-accelerated system which moves more or moves less once the isotropy of SOL of one system is assumed considering what has been accelerated from where.
Out and back Speed of light
[1] Michelson, A. A., Pease, F. G., & Pearson, F. (1935). "Measurement of the Velocity of Light in a Partial Vacuum." Astrophysical Journal, 82, 26.
[2] Essen, L., & Gordon-Smith, A. C. (1948). "The Velocity of Propagation of Electromagnetic Waves Derived from the Resonant Frequencies of a Cylindrical Cavity Resonator." Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 194(1038), 348-361.
[3] Evans, J., & Eisenhower, E. (1951). "An Interference Method for the Measurement of the Speed of Light." American Journal of Physics, 19(4), 356-359.
[4]. Hall, J. L., & Borde, C. J. (1976). "Measurement of the Speed of Light Using Laser Techniques." Applied Optics, 15(2), 300-304.
Test of Sagnac effect
Test of time dilation twin effect
[6] J. Bailey “Measurements of relativistic time dilatation for positive and negative muons in a circular orbit” Nature, 268-5618,pp. 301-305, (1977).
[7] D. Hasselkamp, E. Mondry, A. Scharmann, “Direct observation of the transversal Doppler-shift” A. Z Physik A, 289: 151, (1979).
[8] B. Botermann et al, “Test of Time Dilation Using Stored Li+ Ions as
Clocks at Relativistic Speed” Phys. Rev. Lett. 114, 239902 (2015).
Relevant answer
Answer
SQ: <<So I think it is the case to understand what are the conclusions of SR about the result of the proposed configuration.>>
Yes. Anybody interested has got the opportunity to read my former posts.
Eg. #9 on p. 461 [my first of July 3, 2024] within
proves reciprocity of time delay in SRT.
The scenario of the preprint is analysed in MANY OTHER of my posts.
  • asked a question related to Two Way
Question
1 answer
I am running a two-way mixed anova analysis with one IV is a between-subjects variable and another is a within-subjects variable (each participant was measured six times) and find a significant interaction effect. What should I do to interpret the interaction? I have find similar papers and it says that we should calculate the slope for each participant as shown in the picture, but how?...I am really confused...
Relevant answer
If you obtain an overall p value less than 0.05 for the total ANOVA, you then do pairwise comparisons between the variables to find out which have significant interactions. You don't need to do anything with slope values :)
  • asked a question related to Two Way
Question
3 answers
Greetings, I am final year BSc.(H) Psychology. I used two-way, repeated measures ANOVA for a 2x2(time x intervention) pre and post-test model for my study. Now, within-subject effects of time and intervention are significant. However, the significance level of time*intervention is (0.67). How do I interpret these results?
Relevant answer
Answer
You have detected differences in the groups and a change in the outcome over time, but neither of these effects is related to the intervention. In a pre-post design the interaction is a test of the intervention because you'd expect the pre intervention scores to be similar (especially in a randomized design) and so the intervention effect should show up in the post scores only. This effect (the group difference on post minus the group difference on pre) is the intervention effect and what is tested by time*intervention.
One puzzle is that the groups differ at pre as well as post which suggests its not a randomized design (or you were unlucky).
  • asked a question related to Two Way
Question
3 answers
..
Relevant answer
Answer
Dear Doctor
"Method to overcome the problemThe vanishing gradient problem is caused by the derivative of the activation function used to create the neural network. The simplest solution to the problem is to replace the activation function of the network. Instead of sigmoid, use an activation function such as ReLU."
  • asked a question related to Two Way
Question
4 answers
In my model air is the continuous phase and inert particles are injected from top of the tower using DPM. Source terms options have been selected in the DPM settings. Air velocity profile is displayed properly but air temperature profile is not ?
Kindly suggest any solution.
Thank You
Relevant answer
Answer
Hi Divit Karnawat.
I'm simulating a water injection into a tank, and currently, I have the same problem. I parametrized the velocity and mass flow as a profile based on a transient table, but the temperature doesn't show this option. Did you find a solution? Please, I hope your answer.
Best Regards
  • asked a question related to Two Way
Question
1 answer
Hi there,
I am able to run a one-way ANOSIM test in R (vegan package) but I do not know how to carry out a two-way ANOSIM. Here an example for my one-way test for factor Year on my dataset:
  • results= anosim(dataset, dune$Year, distance = "bray", permutations = 9999)
  • results
I wish to include a second factor, e. g. Zone, for the two-way analysis.
Can anyone help me on that?
Thanks in advance!
Miquel
Relevant answer
Answer
I am also interested how to perform a two-way ANOSIM in R (ideally using vegan package). Any reply to this?
So far, I did it using PAST software (https://www.nhm.uio.no/english/research/resources/past/) but I would appreciate an R-code.
  • asked a question related to Two Way
Question
1 answer
Dear all,
as part of my Master thesis, I am conducting a two-way repeated measures ANOVA on data from a social evaluation paradigm. The purpose for running this analysis is to investigate whether social feedback prediction (like, dislike) moderates the impact of social feedback valence (negative, positive, neutral) on participants' self-rated state self-esteem (i.e. whether unexpected social feedback exerts a differential impact on state self-esteem depending on the feedback valence).
Participants undergo several trials in which they are instructed to make predictions as to the social feedback they will receive, after which they receive alleged social feedback on a personality profile. After a random number of trials, participants need to rate their state self-esteem with reference to the previous social evaluations.
The analysis revealed a significant interaction effect between social feedback valence and social feedback prediction on state self-esteem. I have already plotted this interaction effect using a bar chart, but I would like to quantify the mean differences in state self-esteem between levels of feedback prediction for each level of feedback valence such that I can clearly describe the underlying simple effects and, accordingly, interpret the cause of the interaction effect.
Which methods/procedures/strategies would you recommend using to probe the valence x prediction interaction effect?
I hope that I have provided sufficient information.
Thank you very much in advance.
With warm regards,
Marius
Relevant answer
Answer
Use the emmeans or lsmeans option in the software you are using. This is a post-hoc test after the anova, and accounts for the repeated-measures nature of the model. Often you can get confidence intervals for the e.m. means. Plotting or reporting these intervals with the e.m. means is useful for the reader.
  • asked a question related to Two Way
Question
3 answers
Years ago, to know the work of other researchers we had only two ways: attending conferences and reading the publications (hard copy at that time) on the renowned journals.
At present, why we still consider the process of publication? A lot of predatory journals, many open access journal accept papers in so few days that a normal peer review process is debatable.
A couple of reviewers are really better than what any researcher can comment (with positive or negative meaning) if you download on RG or LinkedIn?
Is it still worth for some specific reasons or just for the academic goal "Publish or Perish"?
Relevant answer
Answer
I think that the classical peer-review/publishing approach only makes sense if it is extremely rigorous on every aspect of the review. That is, peer-review only makes sense if it actually is a quality guarantee, like with an ISO standard to follow, but time has shown that it is very far from it. I'm not even considering predatory journals and the like, as even top journals have shown to be prone to publish the most ludicrous stuff, with the most obvious problem being that reviewers don't really know anymore anything at all these days (so a lot of obvious or old stuff gets published again, not to mention completely wrong stuff). Obviously, there might be differences between fields, but it is especially so in STEM.
One should also take in mind that research and the relative publishing (should) have nothing to do with employment and career paths, at least officially. So, when we think about it, we should not, honestly, try to fix it in order to make it work as a job market tool. I hold this truth to be self evident.
So, the relevant question is, in my opinion: how do we save research and publishing from the misuses that make it today so low quality? My answer is that, unfortunately, we can't, or at least not yet as of today. We currently live in a society that has had a repentine shift in a lot of paradigms, with the result that we failed in preserving the cultural background of most aspects of our life because of the speed. So, the current society, not anymore aware of the past, needs to understand from failure what could have been preserved by culture.
I think that a suitable model could be just like a wikipedia, with each article being an independent and dynamic entity, subject to fully tracked non blind reviews from whoever thinks to do so and the relative changes exposed. Most importantly, nobody can impose anything on the original author. But this will probably never happen in the near future.
  • asked a question related to Two Way
Question
1 answer
Kindly quote some reference
Relevant answer
Answer
ANOVA (Analysis of Variance) is a statistical test used to analyze the difference between the means of more than two groups. A one-way ANOVA uses one independent variable, while a two-way ANOVA uses two independent variables.
  • asked a question related to Two Way
Question
7 answers
I am investigating whether two independent factors with only two levels each affect my dependent variable memory performance. Thus, I performed a two way analysis where my IV1 was significant and the interaction between both IVs.
I am confused regarding post hoc tests as some state no post hoc tests are needed in case of only two levels. Others state that Tukey test should be performed. However, the Tukey does not seem to make sense in case of only two levels in each IV? I thought about doing an independent samples t test? But in this case only further investigate the main effects. Thus, my question is if my analysis requires a post hoc test and if so, which post hoc test would you suggest for the main effects and interaction effect?
Thanks!!
Relevant answer
Answer
  • Yes, the general advice is that if the interaction is significant, you don't need to conduct post-hoc tests on the main effects. Simply, it's because post-hoc tests on the main effects won't be of much interest since you know that there is an interaction effect. But there's no law about this.
  • E.M. means in R are easy to get. For example,
library(emmeans)
marginal = emmeans(model, ~ Instructor + Supplement)
pairs(marginal, adjust="tukey")
  • In R, it appears the the TukeyHSD function in the native stats package works fine when there are only two levels of a treatment.
  • The results from emmeans with the "tukey" adjustment will be the same as the classic Tukey HSD test for a standard two-way anova.
  • In general, I would avoid using pairwise tests (e.g. pairwise t-tests) for post-hoc testing. It's better to use post-hoc approaches that take into account all the data together. But also, when you have very flexible approaches like using emmeans, there's no need to worry about Tukey's HSD or Dunnetts, and so on.
  • asked a question related to Two Way
Question
7 answers
To make a correct design for my study.
Relevant answer
Answer
Dear Alok, thanks a lot for your answer.
  • asked a question related to Two Way
Question
3 answers
Is it possible to model Two-way Left Turn lane in VISSIM?
Relevant answer
Answer
Yes, it is possible to model a Two-way Left Turn lane (TWLT) in VISSIM, a microscopic traffic simulation software. VISSIM provides the flexibility to represent various roadway configurations, including TWLTs. Here's a general approach to modeling a TWLT in VISSIM:
1. Define the road network:2.Specify lane configurations: 3. Configure intersection behavior:4. Define vehicle types and demand: 5. Calibrate and validate the model
  • asked a question related to Two Way
Question
6 answers
I would greatly appreciate it if you could recommend measurement methods for assessing two-way causality in panel data. If there are any corresponding software packages or specific steps for conducting such analyses, it would be highly appreciated.
Relevant answer
Answer
I read an article on arXiv that proposes a new estimator for the average causal effects of a binary treatment with panel data in settings with general treatment patterns.
  • asked a question related to Two Way
Question
2 answers
I am doing my thesis and in my design I have two independent variables, both with 3 levels (no frame, low and high). In the model I am also using the two-way interaction between these two and the two-way and three-way interaction with moderators (party preference and political trust). I found some tutorials online that say I should code the independent variables as a set of two variables to use both in the regression model (D1: no frame (0), low (1), high (0) and D2: no frame (0), low (0) and high (1)). However, when I enter D1.1 and D1.2 for independent variable 1 and D2.1 and D2.2 for independent variable 2 into the model, SPSS exlcudes one of the variables in the output (D1.1).
Moreover, I am not sure how to code and add the interactions to the model. Initially, I coded one variable for each independent variable as follows: no frame (-1), low (0), high (1) and used these for the interactions. Is that also an option, or does this cause problems?
Relevant answer
Answer
Hello Bieke,
If you genuinely believe that the unit difference separating "no frame" and "low" is exactly the same as that separating "low" and "high" for an IV, then yes, you may code them as -1, 0, 1 (or any other linear transformation thereof). However, if you don't believe this, then you must opt for recoding, replacing a three-level variable with two dummy variates.
I suspect that the reason one of your variables is being dropped is due to redundancy, and this could be caused by: (a) no instances of one of the three categories in the data set; (b) IV1 and IV2 are redundant in some way (e.g., every case is in the same level for both variables); (c) a mistaken recoding.
Are you also including all four of the dummy variate products to capture the information about their interaction?
Good luck with your work.
  • asked a question related to Two Way
Question
7 answers
Hello,
I am currently analyzing data from a study and am running into some issues. I have two independent variables (low vs high intensity & protein vs no protein intervention) and 5 dependent variables that I measured on two separate occasions (pre intervention and post intervention). So technically I have 4 groups a) low intensity, no protein b) low intensity, protein c) high intensity, no protein and d) high intensity, protein.
Originally I was going to do a two-way MANOVA as I wanted to know the interaction between the two independent variables on multiple dependent variables however I forgot about the fact I have two measurements of each of the dependent variables and want to include how they changed over time.
I can't seem to find a test that will incorporate all these factors, it seems like I would need to do a three-way MANOVA but can't seem to find anything on that. So I am thinking of a) calculating the difference in the dependent variables between the two time stamps and using that measurement for the MANOVA or b) using MANOVA for the measurement of dependent from the post test and then doing a separate test to see how each of the dependent variables changed over time. Is this the right line of thinking or am I missing something? When researching this I kept finding doubly multivariate analysis for multiple observations but it seems to me that that only allows for time and one other independent variable, not two.
Any guidance or feedback would be greatly appreciated :)
Relevant answer
Answer
Hello Isabel,
The basic design is a two-between (intensity, 2 levels; protein, 2 levels), one-within (occasion, 2 levels) manova. Between-within manovas are sometimes called "doubly multivariate."
So yes, you have three factors.
However, you may wish to consider a couple of points:
1. Do you really intend to interpret the results across arbitrary linear composite/s of the five DVs (generated by the software to maximize the variance accounted for by the between-subjects IVs), or would you prefer to address how the study factors influence scores on each of the five DVs? The first calls for the multivariate test; the second calls for univariate tests.
2. Consider using the pre-intervention score for a given dependent variable as a covariate, then use the post-intervention score as the DV score. This eliminates the within-subjects factor, and offers the ability to "adjust" for randomly occurring differences at the outset among the four treatment combinations.
3. In general, tests of change over time (e.g., meanT2 - meanT1) force you to work with difference scores that are less reliable than either of the scores from which they are derived, unless all time scores are perfectly reliable (no measurement error), which is seldom if ever the case.
Good luck with your work.
  • asked a question related to Two Way
Question
11 answers
I am trying to simulate the blood flow in arteries by two way FSI (Fluent and Transient Structural). Every time I get the error of this sort:
"(DP 0) Element 191 located in Body "Solid" (and maybe other elements) has become highly distorted.  You may select the offending object and/or geometry via RMB on this warning in the Messages window.  Excessive distortion of elements is usually a symptom indicating the need for corrective action elsewhere.  Try incrementing the load more slowly (increase the number of substeps or decrease the time step size).  You may need to improve your mesh to obtain elements with better aspect ratios.  Also consider the behavior of materials, contact pairs, and/or constraint equations.  If this message appears in the first iteration of first substep, be sure to perform element shape checking. Named Selections for the offending element can be created via the Identify Element Violations property on the Solution Information Object."
I tried reducing the time step but it did'nt work. I am new to this field of FSI.  Any help to solve this issue would be appreciated.
Relevant answer
Answer
This error can have several reasons. One of the reasons is applying sudden pressure from the fluid to the solid part in the initial time steps. Defining an extra stiffness at the initial time steps (i.e., ten times higher) can be helpful to end this issue.
This additional stiffness help to prevent distortion due to the suddenly increased force in the interface of solid and fluid parts, and, after 1-5 time steps, disappear and reach to normal stiffness of the materials.
  • asked a question related to Two Way
Question
1 answer
Dear all,
I wanna simulate the two-way shape memory effect.
I found some examples in ANSYS Help, but they're all one way shape memory effect.
So is it possible to simulate two-way shape memory effect?
Any information will be appreciated.
Thanks:)
Relevant answer
Answer
Shuo Yuan , from what I recall the version of the Auricchio model that is available in ANSYS cannot be used to simulate the two-way shape memory effect. In order to do that you could either write your own material sub-routine or try to mimic this effect by using different coefficients of thermal expansion for each phase (the latter is suggested only for investigation purposes and should be considered as a simplistic and approximating approach).
Best regards,
Anargyros
  • asked a question related to Two Way
Question
1 answer
Hello everyone, I've come across a complication while doing some data analysis and was looking for some advice and interpretations.
I need to a run a two way ANCOVA on some data; I'm testing the effects and interactions from 2 independent variables, and our experiments were performed on samples that came in multiple batches so values representing untreated samples per batch need to be included as a co-variate in order to account for batch variation.
I've needed to run these models for analysis of different metabolites in the samples. But there is significant heteroscedasticity and heterogeneity of variance in multiple analyses. I have tried transforming values, but this hasn't worked ( in some cases this even violated normal distribution).
I have found that if there are heterogenous variances in your models then you can either: carry out a two way ANCOVA with robust standard errors (HC3 or HC4) , or weighted least squares regression. However, there are no specific details on how to perform these in SPSS, or how to interpret any outputs.
I am certainly not a statistician, therefore I'd like to run my queries by the community so I can determine the best way forward. Therefore, the main questions I have are as follows:
1. How do you perform a two way ANCOVA with robust standard errors in SPSS version 25?
2. What exactly does the robust standard error accomplish; does it provide homogeneity to your dataset or does it just give confidence intervals and outputs that are appropriate for heterogenous data? (again, I'm no statistician so I'm not very familiar with these terms)
3. After applying robust standard errors, can I still use the 2 way ANCOVA to report my data? Or will a non-parametric test need to be used?
Any help or advice would be massively appreciated, thank you in advance for your attention.
Relevant answer
Answer
Hi
Have your reached any conclusion? Currently, I am experiencing similar difficulty.
  • asked a question related to Two Way
Question
5 answers
While testing assumptions, Shapiro-Wilk Test failed. However, I proceeded with the analysis and the interaction effect was significant.
During our course- lectures, it was mentioned that Anova is robust to violations of Normality.
I seek some references in this regard. (In case we get some support for repeated measures Anova, nothing like it).
Relevant answer
Answer
I have the same question! although may manuals and websites state that it is robust there don't seem to be any peer reviewed references for two- or three-way ANOVA. I can find a couple of references for one-way and RM ANOVA (PMID 36695847 & 29048317). How would you justify carrying out an ANOVA on non-normal data in a paper/thesis?
  • asked a question related to Two Way
Question
3 answers
Hi,
Im stuck with a statistical question of one subchapter:
We have two groups surgeons versus non surgeons. We test the sensibility of the hand with wearing different size of gloves: fitted, undersized, oversized, and comparing them to bare hands (control).
Our questions are:
1) does glove fit alter the sensibility?
2) is sensibility of undersized gloves comparable to bare hand?
3) is there a difference in sensibility between surgeons and non surgeons when wearing gloves?
I believe that the control group=bare hands has to be excluded in the Two Way analysis, regarding to the question 1) and 3) since they require wearing gloves. Should the Question 2) analyzed separately with a one way ANOVA?
Thank you very much!
Relevant answer
Answer
Yes, you should include your control group when doing any analysis because you will want to know if there is a difference between the control group and the experimental conditions. For example, you would have no way of knowing if having a bare hand is different than wearing an oversized glove. By including your control group it allows you to statistically determine if there is (or is not) a difference.
You could still use a two-way ANOVA with your questions, though. Here is what I would do (use your judgment for your own research)
1). Glove fit + surgeon status as predictor of sensitivity
This will give you a comparison of is a surgeon with no gloves has different sensitivity compare to non-surgeons who have over-fitted gloves, etc.
2). Will be taken care of in the above analysis. When you run your two-way ANOVA, be sure your analysis will report interaction effects and multiple comparisons.
3). This will also be taken care of in the first analysis.
A two-way ANOVA with interaction effects and multiple comparisons will report if there is a difference between surgeons and non-surgeons' sensitivity while wearing gloves of different thicknesses.
I hope this helps.
  • asked a question related to Two Way
Question
2 answers
EDS analysis gives the elemental composition in two ways. Should we mention weight % or atomic % for publication in journals
Relevant answer
Answer
It is preferable to present both wt% and at%. How you use the data depends on what you want to show. If you want to identify the presence of a compound, the use of at% will allow you to obtain the chemical formula. If you are checking elemental levels in an alloy, then wt% is used.
  • asked a question related to Two Way
Question
2 answers
  • There are several studies which concluded that New Particle Formation provides 50% of CCN. But conversion of aerosol precursor gases to particle state will take place either of the two ways which are New Particle Formation and Condensation on precursor gases on Pre existing particles. Under what conditions, particular phenomenon dominates?
Relevant answer
Answer
Attachment:
M1 is the smallest particle, which is the smallest theoretically and experimentally: indivisible: m1 ≠ mx+my.
The smallest particle ≠ the basic particle in the experiment.
The smallest particle m1 is proved by "theory and reality", that is, the universe must contain the smallest particle m1.
  • asked a question related to Two Way
Question
6 answers
Hello everyone,
we conducted a 3-way mixed ANOVA and got significant results for the main factors and the two-way interactions. However, the box test of equality of covariance matrices is significant as well. In his book "Discovering statistics using IBM SPSS statistics : and sex and drugs and rock 'n' roll", Andy Fields proposes to employ "robust methods" in that case, which is only possible using R packages (however, he doesn't precise what one would need to do exactly). Others say that often, mixed ANOVAs are done anyway and the violation of assumptions is reported in the discussion part (https://statistikguru.de/spss/mixed-anova/varianzgleichheit-ueberpruefen.html).
I am not sure how to interpret my results. Do you have any suggestions what to do?
Thank you in advance!
Hannah Bauer
Relevant answer
Answer
Hello Hannah Bauer. Given that your discipline appears to be psychology, and given that you are reading Andy Field's book and looking at a website with spss in the address, I'll guess that you might be using SPSS as your primary stats package. If so, have you considered using the MIXED command rather than GLM? MIXED has options for allowing/modeling heterogeneity of variance. Take a look at the examples on these two UCLA pages.
HTH.
  • asked a question related to Two Way
Question
7 answers
As you know, the clouds seeding in the world is carried out in two ways; the classic method and the new methods like ionization method. The classic method is what's happening in nature, and actually adds substances such as silver iodide to the cloud, resulting in the cloud seeding and precipitation. I think that the World Meteorological Organization and scientific organizations around the world accept the classic method , but artificial ionization production is doubtful, especially as it is said that the ionization method is harmful to the environment and maybe it be a controversy like carcinogenicity Or earthquake increase.
Relevant answer
Answer
Better to replant the native Pseudomonas bacteria host plants, as those bacteria are the best cloud seeders on the planet. Image of a cloud being born here in California. Read article at https://www.discovermagazine.com/planet-earth/does-rain-come-from-life-in-the-clouds
  • asked a question related to Two Way
Question
5 answers
Hey everyone
I'm planning a study in which the primary statistical analysis will be a two-way repeated measures ANOVA (as there will be 2 different treatment groups and the outcome will be measured at many timepoints). We are more interested in the between-groups effect, rather than different timepoints within one group.
I'm stuck with the sample size calculation and I couldn't find many helpful resources online. Has anyone had to do something similar and could help me a bit?
Relevant answer
Answer
Hi,
Software Gpower has modules on ANOVA.It is free to use.
Here are some good books on this subject:
Meinhard Kieser Springer Series in Pharmaceutical Statistics Methods and Applications of Sample Size Calculation and Recalculation in Clinical Trials Springer2020
Rens van de Schoot European Association of Methodology Small Sample Size Solutions: A Guide for Applied Researchers and Practitioners Routledge2020
J. P. Verma, Priyam Verma Determining Sample Size and Power in Research Studies: A Manual for Researchers [1st ed.] Springer Singapore; Springer2020
Shein-Chung Chow, Jun Shao, Hansheng Wang, Yuliya LokhnyginaChapman & Hall/CRC biostatistics series Sample Size Calculations in Clinical Research, Third Edition [3 ed.] CRC Press; Chapman and Hall/CRC 2017
  • asked a question related to Two Way
Question
2 answers
I hope I can clearly articulate my stats woes! I am having difficulty interpreting findings related to a significant three-way interaction. My study includes one between-subject variable with 2 levels (Group 1 and 2) and three within-subject variables (Emotions with 3 levels, Stimuli Modality with 2 Levels, and Intensity with 2 levels). The DV is accuracy. I have found significant main effects on all 4 variables, a significant 3-way interaction between Emotion, Stimuli Modality, and Intensity, and the following two-way interactions: Emotion X Stimuli Modality and Emotion X Intensity. Based on the SPSS output for the 3-way interaction, the contrasts show that Emotion at level 1 is significantly different from level 2 and 3 (but Emotion at Level 2 and 3 is not significant) across Intensity and Stimuli modality. This pattern of results is consistent with the 2 significant two-way interactions (I.E., Emotion X Stimuli Modality and Emotion X Intensity). Is there a way to examine simple two-way interactions/effects on SPSS? I know that if the three-way interaction included group, I would have been able to split files based on group and re-run the ANOVA on spss, but I cannot figure out how I would do this with the 3 within-subject variables. I have a screen shot with graphs that show the 3-way interaction. Thanks in advance for your help!!!!
Relevant answer
Answer
Tania Fernandes You want to see effects for all two-way interactions in the SPSS output, is that correct? If so, you want to do the following:
1. Analyze > General Linear Model > Univariate
2. Enter all independent variables and dependent variables
3. Select "EM Means"
4. Move all the items listed in the "Factor(s) and Factor Interactions" box over into the "Display Means for" box on the right
5. Check the box next to "Compare Means"
6. Below "Confidence Interval Adjustment" select the "Bonferroni" option
7. Click Continue
8. Click OK
  • asked a question related to Two Way
Question
8 answers
For my thesis I'm trying to find out whether there is an interaction between age group and scores on the production of different syllable structures.
Since my data doesn't meet the normality assumption for the two-way repeated measures anova I am looking for a non-parametric alternative. My data looks like this: five different age groups and 4 related dependent variables/syllable structures (they are related because they are of increasing complexity). The data of one of the dependent variables is not normally distributed, so therefore I want to use a non-parametric alternative.
I tried the Friedman's test but it doesn't seem possible to add age group as a factor, so then I only compare the syllable structure scores, without a possible interaction with age.
Does anyone know what test I could use if I want to assess the interaction between age group and production scores?
Relevant answer
Answer
Daniel Wright , I would bet the reason is that no such "large step" is seen here. Texbooks are full of stupid sentences like "the WMW-test is the non-parametric alternative of the t-test" and "if you want to do a t-test but your data is not normal distributed, then you can use the WMW-test instead", or even: "if you want to compare two samples and you cannot ensure that the data are normal distributed, use the WMW-test" and so on. This has left behind its traces...
  • asked a question related to Two Way
Question
2 answers
I have to run a robust two-way repeated-measures ANOVA (in detail, a 2 X 3 design) with the package 'WRS2' on R (https://cran.r-project.org/web/packages/WRS2/index.html). However, in the tutorial article, there are only guidelines for the one-way rmANOVA. Is it possible to run such rmANOVA (by instance, using the 't2way' function and related lines)?
Relevant answer
Answer
Helllo,
please check the book Rand Wilcox (2017) - Introduction to Robust Estimation and Hypothesis Testing, chapter 8.6 Between-by-Within and Within-by-Within Designs.
Best,
Rainer
  • asked a question related to Two Way
Question
8 answers
I am looking for a measurement scale to assess two-way communication in the context of leadership in organisations. Is there any commonly used scale for it that can be used in an empirical study?
Relevant answer
Answer
Measurement refers to the assignment of numbers in a meaningful way to variables. We have four scales of measurement: Nominal, ordinal, ordinal and ratio scales. The choice of scale depends on what you are looking for.
  • asked a question related to Two Way
Question
4 answers
Hello all,
I'd greatly appreciate any help to clear my confusion about two-way crossed and nested design!
I am counting the abundance of each common genera of microalgae from the mangroves and tidal flats of 2 different sites, 1 sandy and oligotrophic, and the other muddy and eutrophic. The data that I have collected look like this:
1. muddy site - mangrove (n=6)
2. muddy site - tidal flat (n=8)
3. sandy site - mangrove (n=6)
4. sandy site - tidal flat (n=8)
And each set of data is a genus-abundance matrix.
I have always thought that my design is two-way crossed, but was just made aware that it could be a nested design, since the data obtained from say, muddy-mangrove is dependent on it being in the muddy site...
Is this a nested design, afterall? I read that sample sizes must be equal for a nested ANOVA, is that also a requirement for ANOSIM?
Thanks a lot in advance!
Relevant answer
Answer
Yes, you have sampled both levels of each factor (sediment sandy/muddy, mangrove presence/absence) for both levels of the other, so it is a crossed design.
ANOSIM doesn't require a balanced design (though imbalance may lead to a loss of power).
Comparing the R values in a 2-way crossed ANOSIM will allow you to assess the relative strengths of the effects of sediment (removing effect of mangroves) vs the effect of mangrove (removing the effect of sediment).
  • asked a question related to Two Way
Question
2 answers
if i am studying the changes in the physicochemical properties of chips in different packaging materials then tested its properties after 3, 6, 12 days, is it right to use two way anova? The samples in each packaging was tested having 3 replications.
Relevant answer
Answer
  • asked a question related to Two Way
Question
5 answers
As shown in the image, I have no significant three-way interaction, but all three two-way interactions are significant. Does this mean that I can only report on the interactions between the terms, but not on the effects of the Region & Form terms (both of which are highly significant)?
Relevant answer
Answer
Usually when you have a significant interaction (e.g. Region x Gender), it is the effect of this interaction that is of interest, and the main effects (e.g. Region) are less of interest, because, in this case, we know that the effect of Region changes across levels of Gender.
  • asked a question related to Two Way
Question
1 answer
I am working on the effect of rainfall variation and warming on species composition. I want to test for whether there are significant differences in the single effect of the rainfall variation and warming and in their interaction on species composition (6 treatments in 3 replicates). I would appreciate if you could guide me through the right analysis to use. Thank you.
Relevant answer
Go to YouTube. You will find many examples of using two way Anova.
  • asked a question related to Two Way
Question
2 answers
SSRN has two ways of uploading papers. One is before publishing(WPS) and other is published paper. The supporting Team of SSRN stated that after uploading paper you can not transfer the copywrite to other journal. If we upload published paper in SSRN, IS IT REQUIRED COPYWRITE?
Relevant answer
Answer
If it is a copyrighted work, you have to seek permission from the owner of its copyright before you publish it in your journal. Otherwise your action will fall in the infringement of the copyright.
  • asked a question related to Two Way
Question
5 answers
hello
I am learning fortran.
and wrote a cod for integration of (for example )sin^2((3pi)*x) from 0 to 2 .
I used two way for that
1) rectangle rule
2) trapezoid rule
but I doubt it works properly or not .
I need help for check it
thank you for your help.
Relevant answer
Answer
In general, when a curve is concave down, the trapezoidal rule will underestimate the area because when you connect the trapezoid's left and right sides to the curve, and then connect those two points to make the trapezoid's top, you'll be left with a little space above the trapezoid.
The trapezoidal rule employs function values at nodes that are equally spaced. It is extremely precise for integrals over periodic intervals but is frequently wrong in nonperiodic circumstances.
The Trapezoidal Rule is the average of the left and right sums, and it typically provides a better estimate than either alone. Simpson's Rule approximates area by using intervals topped with parabolas; hence, it delivers the precise area beneath quadratic functions.
However, if the integrand is concave up (i.e. has a positive second derivative), the error is negative and the trapezoidal method overestimates the real value.
I suggest to see the following tutorials as well:
  • asked a question related to Two Way
Question
6 answers
If I have certain score then measured it individually, grouped , teamed scoring, for 2 groups experimental one and controls , Can I apply 2 way repeated measured ANOVA or not?
I have 2 groups experimental group and controls. I measured a certain score for every participant on individual, then if he is in a small group , then at a big team, in that case may I consider the difference in situation from individual case to group to team is like a time factor and the experiment is like a condition to satisfy all requirements of 2 way repeated measures ANOVA
Relevant answer
Answer
Thanks so much dear professor
  • asked a question related to Two Way
Question
1 answer
How do we know which of the two analysis is the most appropriate method in modelling the intervention effects? What is the difference between these two methods?
  • asked a question related to Two Way
Question
1 answer
Hi,
I am trying to set up two-way MLR assay. Simply mixing two PBMCs which are stained with proliferation dye and leave it for 5 days and run it on FACS. Does anyone can share good protocol for this? Somehow half of seeded cells are dead and I do not see any proliferation.
Thanks.
Relevant answer
Answer
Dear Anna!
Please you look at the protocol:
Two-way MLC
Two-way MLC were set up using various types of cells, i.e. whole blood mononuclear cells, CD2+ cells, CD2+CD16− cells, CD2+ CD4− cells, CD2+ CD8− cells, or cells preactivated by OKT3 stimulation. A total number of 2 × 107 cells was cultivated in cell culture flasks in 20 ml of culture medium with or without 20 U/ml IL-2. Medium was exchanged when its colour changed to yellow, usually once or twice per week. Initial cell ratios between the two populations of allogeneic cells were variable, as indicated in the respective experiments. Cell counting error in the 50:50 setup was < 3%. Cell cultures were analysed for composition of cell populations and subsets at various time points using 21 days as end point.
For proliferation assays and determination of cell numbers after different periods of culture, 2 × 105 cells/well were cultured in 200 μl culture medium in triplicates using 96-well U-shaped microtitre plates. In the one-way MLC, 105 cells, ‘responder’ cells, were mixed with 105 irradiated (30 Gy) allogeneic ‘stimulator’ cells; in the two-way MLC, 105 cells of each of the two allogeneic populations were mixed. Following 2, 4, 6, 8, 10 and 14 days of culture 3H-thymidine (0.5 μCi/well, 5 Ci/mmol; NEN, Dreieich, Germany) was added and plates were incubated for 8 h. Cells were then harvested with an automatic cell harvester (Pharmacia LKB, Uppsala, Sweden). Activity was measured in a liquid scintillation counter (LKB Wallac, Turku, Finland). The data are given as mean ct/min of triplicates ± s.d.
Mixed lymphocyte reaction Patient and healthy control peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque PLUS (GE Healthcare Life Sciences, Little Chalfont, Buckinghamshire, UK). Responder and stimulator cells were labeled with proliferation dyes (CellTrace CFSE and CellTrace FarRed, respectively) according to manufacturer protocol (Thermo Fisher Scientific, Waltham, MA, USA). Isolated PBMCs were stained with their corresponding proliferation dye at a 1:1000 dilution and incubated in the dark at 37˚C for 20 min. After incubation, PBMCs were washed in culture media (Roswell Park Memorial Institute [RPMI] 1640 medium; Mediatech Inc., Manassas, VA, USA) containing 10% fetal bovine serum (FBS; Thermo Fisher Scientific) at five-fold volume of the volume used for staining and incubated in the dark at 37˚C for another 5 min. Stained PBMCs were centrifuged and resuspended in culture media (RPMI containing 10% FBS) at a volume resulting in a final concentration of 1 £ 106 per mL. In the one-way MLR, stimulator cells were irradiated at 25 Gy. Responder and stimulator cells were co-cultured in 96-well plates at a concentration of 1 £ 105 cells per 100 mL each in RPMI media containing 10% FBS for 612 days. On days 6 and 12, 100 mL of the responder/stimulator mixture was removed for analysis using flow cytometry. In the two-way MLR, neither cell population was irradiated [15]. In two-way MLRs using normal healthy controls, both cell populations were plated at a concentration of 1 £ 106 per mL for a total of 2 £ 105 cells per well in 96-well plates unless otherwise noted. In two-way MLRs using patient samples, patient PBMCs were labeled with a single proliferation dye (CellTrace CFSE) and plated at 3 £ 105 cells per well (no addition of donor and recipient cells). The patient PBMC amounts per well were not adjusted by donor chimerism in each patient. In parallel, PBMCs from a single normal healthy control (without mixture of another control cells) were also cultured to evaluate baseline lymphocyte proliferation in the same condition. A unique healthy control without cryopreservation was used in two-way MLR for patient samples, who was not the donor used in the original transplant. Flow cytometry For surface marker analysis, isolated PBMCs were labeled with antibodies against CD33 (clone AC104.3E3, Miltenyi Biotec, Bergisch Gladback, Germany), CD20 (clone L27, Becton Dickson, East Rutherford, NJ, USA), CD14 (clone TUK4, Miltenyi Biotec), CD8 (clone BW135/80, Miltenyi Biotec) or CD4 (clone M-T466, Miltenyi Biotec) for 30 min in the dark at 4˚C. A non-stained control was used to differentiate between positively labeled cells. Analysis was performed using a FACSCalibur flow cytometer (Becton Dickinson). For analysis of lymphocyte proliferation, a forward-scatter/side-scatter plot was used to gate the lymphocyte population. Non-proliferating and proliferating cells were captured in separate gates, and the percentages within each region was estimated (supplementary Figure 1). The proportion of living and dying cells was determined using the percentage of each cell population captured in either the combination of gates 1 and 2 or gate 3 (supplementary Figure 1) after 12 days in MLR culture. (attached file)
  • asked a question related to Two Way
Question
4 answers
Given the independent variable (x) and two regulating variables (M1 and M2), if we want to plot a three-way interaction diagram, which interaction items need to be calculated? After obtaining the estimated parameters of these interaction items, which software or plug-in can be used to draw the three-way interaction diagram?
Thanks & Regards
Relevant answer
Answer
In my lab we use the Jeremy-Dawson excel to plot the three-way interactions. It is an excel template that you only have to introduce the required data.
  • asked a question related to Two Way
Question
3 answers
I'm using two way crossed ANOSIM with Time and Treatment to analyze similarities in and between groups. I chose 4999 permutations but that was an arbitrary decision. I'd like to know how to define the correct amount of permutations and even though I've read some of Clarke's papers (Clarke, 1993. Non-parametric multivariate analysis of changes in community structure) and the PRIMER v.6 manual, I'm afraid I have not reached a clear answer, possibly because of lack of understanding or need of simpler language. I'd appreciate any help.
Relevant answer
Answer
As a general rule (valid for N > 30), the statistical error halves, if the sample size is increased 4fold. I would say, that in randomization tests you get a rough estimate with 250, a reasonable result with 1000 and you are on the safe side with 4000. More than 10000 is rarely necessary. As the default number of permutations of anosim in in R is 999 (+1, the observed case), you don't make anything wrong with 4999.
  • asked a question related to Two Way
Question
5 answers
Hi everyone, I got a theoretical question- is it possible to get a significant three-way interaction in ANOVA without having 3 separate significant two-way interactions? I see this pattern of dependency in my data and I wonder whether it has a theoretical basis, or is it just coincidence?
Thanks in advance
Relevant answer
Answer
In a balanced full factorial design all effects are independent of each other (orthogonal). So the sums of squares attributed to two-way interaction can in theory and practice be 0 and the three-way interaction have non-zero SS and be significant.
Its unusual in practice because in general higher order effects account for less variation than lower order effects. This is the hierarchical ordering principle. Note this is a general tendency that arises for a mix of different reasons - it isn't inevitable:
  • asked a question related to Two Way
Question
19 answers
Hi all. A project I'm working on involves the use of a two-way repeated measures ANOVA. The dependent variable is the transcriptional accuracy of sentences-in-noise (measured in proportions). The independent variables are accents of the sentences (2 accents) and visual primes (2 kinds of primes). The results show that there were significant main effects of primes and accents and a significant two-way interaction between primes and accents (F(1, 30)=9.97, p=0.004). However, as shown in the attached line chart, the two lines are almost parallel. Moreover, post-hoc paired-sample t-tests confirmed that participants' accuracy with accent2(Mean=0.77, s.d.=0.13) is significantly higher than accuracy with accent1(Mean=0.51, s.d.=0.18) in prime 1 condition, and similarly, participants' accuracy with accent2 (Mean=0.68, s.d.=0.13) is significantly higher than accuracy with accent1(Mean=0.31, s.d.=0.12) in prime 2 condition. Does this indicate that the main effects of accent and prime are not dependent on each other? If so, isn't this contradictory with the result suggesting significant interaction? Or is it that the occurrence of a significant 2-way interaction only requires that the difference between the group mean accuracies with accent 1 and 2 was smaller in prime 1 condition than in prime 2 condition, which in this case is true.
Thank you in advance!!!
Relevant answer
Answer
This is a good example of why it's important to not place too much importance on p-values.
The significant p-value tells you that the statistical procedure is able to identify an effect of the interaction against the noise of the variability of the data * . Looking at the plot, your eyes, too, tell you that the slopes are different relative to the variability in the data. The error bars on the red points overlap, and those on the blue points do not.
But this significant result does not tell you that the interaction effect is large, nor that it is of any practical importance. The plot is very helpful for the reader to understand the results. The difference in slopes is small relative to the difference in Accents, and probably relative to the difference in Primes. How you interpret these observations for your reader is up to you.
__________
* This description is not technically correct, but hopefully gives you a sense of the point I'm trying to make.
  • asked a question related to Two Way
Question
3 answers
about this problem , I have followed two ways, ( one way FSI & two way FSI ) but still am getting some issues:
- The fluid effect on natural frequency of the pipe has been obtained, but the effect of fluid properties such as pressure and velocity showed no effect on final result of natural frequency when I changed them. (why?)
Relevant answer
Answer
please follow the link below
  • asked a question related to Two Way
Question
3 answers
difference?
Relevant answer
Answer
To clarify Alan F Rawle's answer:
Particle Size - the physical size of the particle
Crystallite Size - size of a single domain with the same orientation
Therefore, particles typically consist of multiple crystallites.
You are inherently measuring the different definitions above by using different techniques, and therefore MUST differentiate between them. TEM, specifically STEM (s is for scanning), can get you overall particle size. Diffraction within the TEM can give you lattice parameters and in turn the unit cell, however, this is fairly time consuming, complicated, and out of the scope of your question. XRD, by whichever analysis technique (Scherrer, integral breadth, Rietveld, etc.), you are measuring the scattering domain size, i.e. crystallite size.
The condition when particle size = crystallite size is when the particles are single crystals. In my personal experience, this condition rarely occurs. I've measured multiple nanoparticle systems on substrates and compared with XRD, and "agreeable" values are normally 10-30nm different. The reason for this deviation is the inherent broadening of nanoscaled materials in the XRD pattern. Also, in any type of microscopy, there is a limited sample size of particles, therefore counting statistics are poor.
Hope this clears some concepts up!
  • asked a question related to Two Way
Question
3 answers
I have seen that some equation sets have an explicit way of defining the substrate consumption whereas others have an implicit way. I would like to know how to convert the former into the latter.
For instance, in the attached file, it can be seen that there are two ways to describe the growth of bacteria.
In the first (explicit), the presence of a half-saturation constant suggests that the model is a Michaelis-Menten case. The second is straight a logistic model.
I was wondering if I can convert the first into the second, that is explicit to implicit.
Considering that the Monod term says that
μ = μᵢ[S/(S + K)]
then I can write
Ṅ = μN * logistic term
My question is: Would this modification be mathematically and biologically sound?
If yes, how can I estimate the carrying capacity? For instance, if I know the amount of limiting substance, can I estimate the number of cells that a system can sustain?
Thank you
Relevant answer
Answer
You will be best judge I think . There are so many model papers of logistic regression on Michales Menten equation - https://www.youtube.com/watch?v=fv6OAVe2vQc
  • asked a question related to Two Way
Question
2 answers
Hi, I have been trying to run the WRF model for 24 hours over a month (September 2018). I am using three two way nested domains (9km, 3km and 1km) with 63 explicitly defined vertical levels over a part of peninsular India. My timestep is 30. I am getting cfl errors only on some days, while for others the model run is completed without any errors. I have used the same domains and other runtime options for the month of January, 2019 as well and had no issues there. What might be the issue here and how can I attempt to resolve it? Please help me out.
Relevant answer
Answer
I changed my time step to 18 and it worked. Thankyou!!
  • asked a question related to Two Way
Question
5 answers
Hello! I'm running a Friedman two-way analysis because my sample is not normally distributed.
I've performed the analyses on different groups, paired on two periods. One of them, although having a considerable difference between the two periods, is not significant (Friedman 1.3 on 1 degree of freedom). I wonder if this is because this group is smaller (n=22) in regards to the others.
I've looking for evidence on Friedman robustness according to sample size but I haven't found anything substantial.
Thanks!
Relevant answer
Answer
First David Morse is correct in everything he said. I would like to add that robustness of nonparametric tests to similar parametric tests is oftentimes just not true. You might want to look at the attached google search for some studies on the topic. Best wishes, David Booth
  • asked a question related to Two Way
Question
3 answers
I have just performed 2x4 mixed factorial anova (one between= treatment and one within= time) and found treatment*time interaction as significant. To see at which point(s) my treatment generated a difference between my groups, I ran simple effect tests and didn't find any significant difference at any point. I read some threads and discussions but couldn't fully comprehend these results and not sure how to report this. Can somebody help?
Relevant answer
Answer
Mathematically (statistically), it is possible to present interaction effect in absence of the primary effects. Using effect size plots (countered plots) is a good assistant n this case.
  • asked a question related to Two Way
Question
4 answers
Hi all,
I hope you are all doing well. I have a mixed design (2x2) with a Likert (1=I strongly not agree, 5=I strongly agree) scale dv and med based on 3 items. I created one unweighted scale for both variables.
Now I wanted to do a two way mixed anova but when checking for the assumptions (normality etc) it was absolutely not normal distributed when looking at Shapiro Wilk test (sig 0.000) I found out you sometimes can use a summated Likert scale as "interval" but not always, and in my case I think not as I believe my scale is ordinal? Then I was thinking about an ordinal logistic regression but I am not sure if this works for a mixed design. (p.s. both Moderator and IV are manipulated).
Does anyone would like to share their thoughts or have experienced the same issue, let me know!
Kind regards,
Maayke
Relevant answer
Answer
Thank you so much Andrew Paul McKenzie Pegman !
  • asked a question related to Two Way
Question
3 answers
Hi will there be any difference in pressure values obtained from one-way FSI, Two-way FSI, and CFD Analysis only? If yes/no, may I know what can be the reason Thank you
Relevant answer
Answer
Deepak Kumar Pandey Thank you Sir for your information
  • asked a question related to Two Way
Question
9 answers
Currently when i run the code i get only the coefficients for independent variables. I dont get the specific intercepts for each entity and each time period. I need separate equations for each entity at each of the time period. What is the procedure or what is the command needed. Please help .
Relevant answer
Answer
you should found a summary () of data before and use the lm and plm functions a
  • asked a question related to Two Way
Question
8 answers
There seems to be vagueness when it comes to the difference between two way repeated measures and generalized linear mixed model (GLMM). As far as I know, when there are no missing values in the data of two independent variables, even if one of them is within and the other is between, there won't be any problem if the two way repeated measures is used instead of GLMM. In my case, there are no random variables but just fixed ones. One of them is time as a categorical variable. The other is treatment as a categorical variable,too. Treatment is a between-subjects variable, whereas time is a within-subjects variable. So, in this scenario, I consider I don't need to use generalized linear mixed model. I just use two way repeated measures, since there are no missing values. Is it correct ?
Relevant answer
Answer
Thank you for your time and help Dr. Jos Feys
I've just opened the data and run a series of simulations with different means, standard deviations and sample sizes through rnorm() function. Now, I understand the difference better. As far as I understand, we can say that an ANOVA is a kind of analysis depending on a linear regression. I mean an ANOVA is a special case of GLM. That's all. Thank you for sharing it. It helps a lot.
  • asked a question related to Two Way
Question
6 answers
Hi everyone. I am doing a two-way FSI analysis of bearing (Fluent + Structural). Can anyone tell me how to decide the values for RMS convergence target and Under relaxation factor in the system coupling? On what basis these values should be decided, Kindly help
Relevant answer
Answer
Harish Kamath , Do you mean one-way FSI? As far as I know, steady-state analysis is defined as one-way FSI, and system coupling is no longer needed. In these simulations convergence is controlled by pressure-velocity coupling scheme and URF.
  • asked a question related to Two Way
Question
8 answers
i have two IVs and four DVs, initially, i was going to run a two way manova test but my DVs are not correlated, so i was told it's better to do individual two way anova for each DV.
however, spss won't divide my IV (religion) into the values '1' and '2', it just shows the output for religion as if it is a one level IV. i also tried split file but there is no report on significance levels when i do that.
I've been stuck on this for two days now :/
Relevant answer
Answer
Hello Hosna,
Can you furnish screen shots of: data view and variable view for your data set? Be sure that the data view shot includes a couple of cases from each level of your religion variable. As well, try running a crosstabs on the two IVs that you're using, and see if that correctly separates the religion levels in your data set.
Good luck with your work.
  • asked a question related to Two Way
Question
4 answers
Was wondering if anyone here can help me out with a problem I've run into with the Arena Simulation software.
Basically, the production process I am modelling has two stations. I want entities to first be sent down Conveyor Line 1. After 21 entities are sent down conveyor 1, I want the next 21 entities to be sent down conveyor 2. Afterwards, the next 21 entities will be sent down conveyor 1 again. And so on and so forth.
So far I've come up with two ways how I might be able to model this process however I am unsure of how to actually go about implementing these ideas. First would be to have alternating entity types. The first 21 will be entity 1, next 21 entity 2, next 21 entity 1, and so on and so forth. Then there will be a decide module checking what kind of entity it is and will act accordingly.
Next idea is to assign a variable/attribute. The next would be to assign a variable that counts the number of entities that pass it. The decide module will then act accordingly.
Any help will be greatly appreciated!
Relevant answer
Answer
Thank you Iyo
Unfortunately you are repeating what you said before. Therefore, for me at least, I am still in the dark
One more: What are entities?
  • asked a question related to Two Way
Question
4 answers
I am conducting a longitudinal study and trying to figure out which analysis should I use. My independent variable are driving anxiety (mock test/ official test), financial distress, and dependent variable performance (succesful/unsuccesful). I thought a two-way repeated measures Anova would be suitable but I got financial distress which is a continuous variable. Any solutions on which test I should use or what should I change ?
Relevant answer
Answer
Categorization of your continous variable would mean reducing information that lies in this variable.
When you are looking for an alternative that can deal with categorical as well as continuous IVs, you should consider Generalized Linear (mixed) Models.
  • asked a question related to Two Way
Question
4 answers
I am modelling a two-way slab that is supported on all four sides with a point load at center. I can't seem to get the right results. Could somebody explain what are the ideal boundary conditions used in two-way slab modelling in ABAQUS?
Relevant answer
Answer
Thank you so much!
  • asked a question related to Two Way
Question
5 answers
As the question said, when I conducted a two-way ANCOVA (pre-test served as covariate) after confirming the homogeneity of regression slopes assumption, a statistical significance was found on the covariates (pre-test score). In this case, how can I interpret the results?
Relevant answer
Answer
In an ANCOVA test the covariate does not vary among the groups of the categorical factor or factors. Assuming that the interaction term is not significant then the assumption is not violated. If the interaction were significant,then you need to use a different approach to analyze this data, such as a mixed model.
  • asked a question related to Two Way
Question
1 answer
I'm looking at various ways to analyse my data and in one form or another, I will be using MANOVA as I have multiple DVs, and two IVs. I'm not sure whether there's a meaningful relationship between the two IVs, therefore I was considering running two one-way MANOVAs instead of running one, two-way MANOVA. I'm looking to know if there's any literature out there to suggest whether running two, one-way MANOVAs (adjusting the error rate with Bonferroni corrections) is better than running one, two-way MANOVA in this situation? I've found papers that do run the tests this way, however I'm struggling to find a rationale why!
Thanks!
Relevant answer
Answer
Hi Rachel
I think you should use a 2-way MANOVA not 1-way MANOVA.
The following is an incredible resource:
  • asked a question related to Two Way
Question
5 answers
Hello,
I am writing a code in MPLUS . I know that we have two ways of defining variance for a latent variable. The first one is letting it to be defined by the variance of one of the indicators, and the other way is by letting the latent variable to be in a standardized form. My question is that what if I have a combination of continuous and categorical variables as indicators?
Thanks,
Zahra
Relevant answer
Answer
In your measurement model, if the latent variable is indicated by both categorical variables and continuous variables. How do you proceed to choose one of the categorical variable fix to 1, or one of the continuous variables?
There is no rule. Choosing a continuous variable may make the interpretation simpler.
If you are trying to fit a one-factor CFA model in MPlus with 1 continuous indicator (values 0-10, and skewed distribution) andlets say ,10 categorical variables (4-option Likert), you may employ ULSMV. You may want to combine continuous and categorical indicators with ULSMV.
  • asked a question related to Two Way
Question
4 answers
Hello everyone,
I have 3 groups and 4 measurements so, I performed two-way repeated measures ANOVA. How can I detect the difference (which groups and which measurements) when there is significant difference in group*measurement in two-way repeated measures ANOVA? How should I perform the post-hoc test?
Relevant answer
Answer
In attachment an R script for your design with the post hoc tests.
  • asked a question related to Two Way
Question
1 answer
I have one group of participants, all of them performing 3 variations of the same movement. I'd like to compare for differences in knee joint angle among those 3 movement variations (conditions) and at 3 time points during each condition. Should I perform two-way repeated-measures ANOVA, two-factor mixed-design ANOVA or another type of statistical test?
Thank you in advance for the answers!
Relevant answer
Answer
Yes, do run a between x within repeated measures ANOVA. In attachments R and SAS programs
  • asked a question related to Two Way
Question
5 answers
I am analyzing data obtained from a crossover study conducted on same animals evaluating the effect of two different anesthetic drugs on heart rate, respiratory rate, pulse oximetry, rectal temperature and etc over several time points from baseline to induction and every 5 minutes during anesthesia. I would like to detect the effect of anesthetic and time therefore a two way repeated measures ANOVA is required. Do I have to assume sphericity or not and use geisser-greenhouse correction method for this analysis in graphpad prism 8? I would appreciate if anyone with similar experience could reply because the significant results vary considerably.
Relevant answer
Answer
I don't see a reason why you could drop the sphericity assumption. Greenhouse-Geisser is a typical solution, and some authors recommend to use it anyways, because you cannot rely on the results from Mauchly test (e.g. Maxwell & Delaney,
2004).
Other alternatives could be an MANOVA approach to repeated measures (Tabachnick & Fidell, 2007) or multilevel modeling. Both have pros and cons, but the latter is apparently the most flexible tool to incorporate different variance-covariance structures.
  • asked a question related to Two Way
Question
6 answers
Hi,
Following a two-way analysis of variance (ANOVA), when can we use Fisher's Least Significant Difference (LSD) test? Is it reliable or explainable showing data? I have some mouse behavior data which show a significant difference only via LSD test. I'll appreciate for your kind advice. Thank you.
Relevant answer
Answer
Assuming you wish to maintain good control over the family-wise alpha, Fisher's LSD should only be used when you have k=3 groups. Only in that case, does it control the family-wise alpha at the per-contrast alpha. David Howell discussed this in his textbook, Statistical Methods for Psychology (many editions available). I believe Thom Baguley also discusses it in his book, Serious Stats. And the following article is another source, if you need citations to convince a supervisor, co-author or reviewer (etc.). HTH.
PS- Fisher's LSD also assumes reasonably good homogeneity of variance, IIRC.
  • asked a question related to Two Way
Question
7 answers
I built a regression model which has a total of 6 risk factors (regressors) and 7 two-way interaction terms. I need to perform a response surface analysis of my specified model which has a total of 6+7 = 13 terms.
However, When I am trying to perform RSM in SAS using PROC RSREG, it is considering all the linear factors, all the second-order factors, and all the two-way interaction factors. So, it is considering a total of 6(linear)+6(quadratic)+30(interaction) = 42 factors. This is the standard way I have seen most of the books/ research articles performing RSM. But don't want to include all the 42 terms. Instead, I just want to include only 13 terms which I have identified in my regression model. Is there any software that does that? Thanks, in advance
Relevant answer
Answer
Aditya Chakraborty, you can consider this R package for RSA at https://www.nicebread.de/software/RSA/index.html
  • asked a question related to Two Way
Question
3 answers
I have got a data of times series(14 continuos variable and 1 categorical variable). I find out to use a Friedman test. but I know that It just has used in Rank and/or Likert data. I am not sure how to include interaction effects between variables. Therefore, I had a clue which could be possible multiply and/or divide for indepent variables so that, it will able to test interaction effects between indepent variables.
For now, I used a friedman.test() and posthoc.friedman.conover.tes() of PMCMR on R-package to test ANOVA test and Post-hoc test. Another hand, I will use AovSum() of FactormineR on R-package or gam() it is Generalized Additive Models of mgcv on R-package.
PD. I tried to use a many R-package however, It doesn´t work with my data.
Pseudocode:
data.aov=ANOVA(depent variable ~ indepent variable 1*indepent variable 2
*indepent variable 3*indepent variable 4*...indepent variable [n-1], data)
summary(data.aov)
Relevant answer
Answer
José Augusto Solís Benites sé Augusto Solís Benites ,Do you have a repeated measure or ordinal/categorized time data? How many IVs(15?), and type of DV. Interaction between what? To me, the tests you are using is inappropriate, misspecification exist, in your model(data.aov) 1. The Friedman test is the non-parametric alternative to the one-way ANOVA with repeated measures. It is used to test for differences between groups when the dependent variable being measured is ordinal. 2. The Jonckheere-Terpstra test is a rank-based nonparametric test that can be used to determine if there is a statistically significant trend between an ordinal independent variable and a continuous or ordinal dependent variable.(if the peruvian fish characteristics can be put in ordered scale.) Except we see the data, know the IV and DV structure, you are the one that knows best what to do, any advice here is off-mark or serious error(meaniless) given your unknown research questions and dataset structure.
  • asked a question related to Two Way
Question
7 answers
I was performing a binary classification problem with 15000 RGB images using a scratch build CNN model. While it comes to evaluate the model, I can do it in two ways:
1. Splitting data Train and Test and use 10 fold cross-validation for the training data. Later with the best model, I would use the unseen Test data. In this way I got appx. 91.5% avg. accuracy for both test and validation.
2. Just use 10 fold cross-validation and got 92.5% avg accuracy(slightly better result than the previous one.)
Which option would be the best for reporting the performance of my model in the research article?
TIA
Relevant answer
Answer
Muhammad Ali Edward Peake Thanks for sharing. I will check them out.
  • asked a question related to Two Way
Question
5 answers
In common view mode, the ground to ground time transfer by Two- Way satellite Time and Frequency Transfer (TWSTFT), What are the different models which reduces the noise of the space clocks?
  • asked a question related to Two Way
Question
5 answers
Drilling fluid is used in drilling operation in two way. One way  is overbalanced and another way is under balanced condition. Both one has pros and cons. I was wondering to know the disadvantages of using drilling mud  in case of  under balanced condition?
Thank You
Note: If anyone has details lecture materials related to drilling fluid lab, Please send to me
Relevant answer
Answer
If one drill well with drilling fluid with mud weight under balanced then there are chances of formation damage due to imbalances of hydro static pressure and formation pressure. Caving may occur which is if not reduced may lead to stuck of drill strings.
  • asked a question related to Two Way
Question
4 answers
The focus of this discussion is software for Football. According Chang (2018), mentioning Carling (2005), generally, performance analysis can be classified into two main categories: notational analysis and motion analysis. The two systems have different focuses. Notational analysis provides factual record about the position of the ball, the players involved, the action concerned, the time and the outcome of the activity, etc. Motion analysis focuses on raw features of an individual’s activity and movement, for example, identifying fatigue and measuring of work rate.
The two systems contribute for the performance analysis which has three main aims:
  1. Observing one’s own team’s performance to identify strengths and weakness
  2. Analysing opposition performance by using data and trying to counter opposing strengths and exploit weaknesses
  3. To evaluate whether a training programme has been effective in improving match performance
Performance analysis is not just about analysing matches and games. It is essential in the training programme to help coaches improve players’ performance. The following figure shows the coaching cycle. Performance analysis plays a key role in this cycle. Starting from the top, “Performance” means the performance in the game or training. “Observation” can be from the coach or video camera. Since research indicates that coaches are able to recall fewer than half of the key incidents that arise during the game, video camera is a better way which can record all the key events (actions and movements) for further analysis. In “Analysis”, it means analysis of data which include data management. For example, using performance analysis software to code the game, editing footages from the camera, extraction of data from data provider, etc. These are the areas in which the performance analyst spent most of the time. The product of this “analysis” stage can be statistical analysis and video recordings. In “Interpretation”, it can be put in two ways according to my experience. It could be done by coach or performance analyst. Some analysts have the authorisation from coach to interpret the data and then write a report or make a presentation to the coach or team. Some coaches just want the data from performance analysts and the coaches will interpret the data by themselves. It really depends on the coaches’ preference and the partnership between the analyst and the coach. After that, “planning” means the coach plan what to do after knowing what went wrong or which part the team did well. The coaches have to evaluate the performance prior to this planning stage. Otherwise, he doesn’t know how to improve the team’s performance in the next match. In most of the cases, it means the planning of the coaching session using the result of the performance analysis. “Preparation” means the execution of those coaching session in the training so prepare the team for the coming game. It will go back to the “Performance” stage and the whole cycle keep going.
What kind of Software or App are you using for Performance Analysis in football? Can you share with us the positives and negatives aspects according your experience?
Relevant answer
Answer
Sportscode, Dartfish.
  • asked a question related to Two Way
Question
4 answers
I'm running a correlation analysis between a set of variables in SPSS.
In a first analysis I ran a crosstab analysis entering variables as rows and columns and performed both Spearman, Kendall's Tau-b and Tau-c correlation tests and annotated the results.
In a second moment I performed the same analysis, but going trough the bivariate correlation option in SPSS to obtain a correlation matrix and to facilitate the view of significant correlations.
It turned out that for Kendall's correlation, the p-values were different between analyses, despite the correlation coefficient and the number of valid samples being identical.
E.g.: For a given correlation I've got Tau-b = 0.175; p = 0.032; N = 75 in the first analysis, but obtained Tau-b = 175; p = 0.067; N = 75. For the Spearman's correlation the results were consistent between analyses, Rho = 0.213; p = 0.067; N = 75.
Can somebody grasp why this occurs? There are differences in p-value estimations when running correlation analyses in these two ways or it is probably be an error?
Relevant answer
Answer
Hello Glauco,
A search of IBM SPSS 24 Algorithms outlines the approximate SE method used to evaluate Tau-b in the Crosstabs subprogram, but no mention is made of what goes on in the Correlations subprogram.
I tried a sample data set with each in SPSS 26: Both yielded the same Tau-b value, but differed in the computed probability under the null hypothesis. Therefore, it is safe to conclude that these two subprograms evaluate significance level differently (and were likely implemented by different developers). Caveat emptor!
Good luck with your work!
  • asked a question related to Two Way
Question
6 answers
We performed an experiment on a number of blood donors. We took the blood from each donor and divided it into 9 equal volumes. Three of the blood samples from each individual were left as controls, three were subjected to treatment A and three to treatment B. We then measured the response in terms of a specific protein or mRNA. This was done for a number of individuals.
We believe this should be done as a two-way repeated measures ANOVA, where treatment (control, Treatment A and treatment b) is one repeated factor and replicate the other. Is this correct? As there are no inherent differences between the three replicates for an individual within a given treatment, we wonder if this affects how to set up the analysis?
Thankful for any help we can get.
Larry Greenberg
Relevant answer
Answer
Hello,Larry
You can use general lineaer mixed model(GLMM) to estimate any within and between effects.
GLMM id more general approach than repeated measures ANOVA .
  • asked a question related to Two Way
Question
3 answers
I'm currently writing the results section of my undergraduate dissertation and I am unsure of the best way to structure it. I have 3 dependent variables, each of which have been analysed with a two way repeated measures ANOVA and Post-Hoc Bonferroni corrections. Would it be better to report all of the ANOVA's in one section, then followed by a second section for the Post hoc comparisons, or would it better to report the results as individual sections for each DV? Any other suggestion would be appreciated.
Thank you!
Relevant answer
Answer
Rowan Board I believe it would be better to report the results for each DV separately. Furthermore, for each of the DVs, you can report the results from both Repeated measures ANOVA and Bonferroni post hoc in a single table.
  • asked a question related to Two Way
Question
3 answers
My experiment has two factors, binary and continuous variables.
The normality test gave p<0.05 for all variables.
Relevant answer
Answer
Please install the function from Github. It has been updated.
Pedro
  • asked a question related to Two Way
Question
3 answers
I want to ask your opinion regarding the use of ANCOVA to analyze data obtained in repeated measure design. In this experiment, the experimenter used a pre and post-test design with intervention and control groups. Accordingly, participants in both groups completed a set of questionnaires, and only the intervention group joined a sort of activity while the control group remained inactive. Lastly, participants completed the same surveys. The experimenter did not prefer to make within-group comparisons but employed 2 (gender: female-male) x 2 (group: intervention-control) two-way analyses ANCOVA to explore whether the post-intervention measures differed significantly between intervention and control groups. The experimenter entered the pretest scores to the model as a covariate.
I wonder whether the pretest scores can be used as a covariate and whether a data obtained via within-subject design can be analyzed via between-subject methods.
Relevant answer
Answer
Pre-test has to be used as a covariate. Therefore the person is correct so long as other assumptions are met
  • asked a question related to Two Way
Question
7 answers
I'm currently working on my under-grad dissertation project, researching whether Raffinose impacts gut barrier function. I have used a control measure and a high, medium and low dose of Raffinose treatment, and tested on Caco-2 cells over a period of 4, 24 and 48 hours. Would I need to use a one-way onova or a two-way onova?
Relevant answer
Answer
to David L. Morgan
Anova : dose df = 2, period df = 2, interaction df = 4 if estimable (not confounded with Residual Error i.e. .
Reg : dose df = 1, period df = 1, interaction df = 1 always estimable.
This because one should use the factors of Anova as quantitative IV in Reg. This is liable iff the response in monotonic. If not, still possible with orthogonal polynomial; but this is an other story.
  • asked a question related to Two Way
Question
3 answers
I don't have advanced knowledge of SPSS and tutorials aren't making much sense to me, if anyone is able to explain SPSS two-way ONOVA step-by-step in the simplest form I would be grateful. My research is based on Raffinose and gut barrier function using TEER values. I have a control measure, high, medium and low dose over a time frame of 0,4,24 and 48 hours. How do I input the data and analyse into a two-way ONOVA?
Relevant answer
Answer
There are several good videos on YouTube, do a search using the search word "Two-way Onova SPSS".
  • asked a question related to Two Way
Question
7 answers
I work with a classic research design that requires a two-way repeated measures ANOVA analysis: 4 different treatments were tested on 15 subjects (all subjects went through all 4 treatments in random order). A given variable was measured at 3 different time points for each treatment (before, right after applying the treatment and 30 minutes after). So I have two within-subjects factors: time (before, right after and 30 minutes after) and treatment (T1, T2, T3 and T4).
A two-way repeated measures ANOVA showed no significant interaction between time and treatment. By curiosity, I ran some one-way repeated measures ANOVAs to see if there was a difference between some trials (between T1-before and T1-right after for instance, or T1-30 minutes after and T2-30 minutes after) and in some of these cases, I see p-values under 0.05. Is this something I have the right to do? Can I report these significant changes even though the two-way ANOVA doesn't look good?
Relevant answer
Answer
I agree with both Michael E Young and Timo Törmäkangas . They both say yes but you have to do it correctly. best, David Booth
  • asked a question related to Two Way
Question
3 answers
Hello,
I have a question related to the two-way MANOVA (850 observations). I conducted a two-way MANOVA for:
2 IVs (continuous)
  • IV1 with 2 levels
  • IV2 with 3 levels
6 DVs (treated continuous, 4 points Likert scale)
In the result, I found that:
IV1 (p = .510, NOT SIGNIFICANT)
IV2 (p = .002, SIGNIFICANT)
IV1*IV2 (p = .009, SIGNIFICANT)
Do you know that If I should discuss both the main effect IV2 and the interaction effect of IV1*IV2? I saw some people said that when we discuss the interaction effect, we don't discuss the main effect of the paper. However, the main effect of IV2 still looks also important to me. Should I discuss it?
Also, I see that SPSS doesn't have the post-hoc test for interaction. Do you know how should I do that in SPSS or R? If I need to do post-hoc test, will we have 6C2 = 15 comparison pairs?
Thank you very much!
Relevant answer
Answer
Hello Anh,
The presence of interaction among factors in anova/manova indicates that marginal means for the main effects do not correspond to the differences between levels of one factor at specific levels of the other factor. Hence, the appropriate follow-up is often referred to as simple effects tests (e.g., each level of factor A can be compared, as in a one-way test first at level 1 of factor B, then at level 2 of factor B, etc.). These tests can be elicited in spss, but you'll need to use syntax, not the dialog box. Here's a good resource on how to do just that: https://www.ibm.com/support/pages/significant-interaction-anova-how-obtain-simple-effects-test
It can be the case that simple effects show the same general trend as does a main effect, except for the magnitude of the differences observed. So, even when a trend is congruent, it still differs (in magnitude) enough that the best information about what's going on comes from the simple effects tests (following up the interaction), and not from the main effects tests.
Good luck with your work.
  • asked a question related to Two Way
Question
5 answers
Collision experiments imply that an electron must be smaller than 10-18 m. The equation for the energy in an electric field external to radius r produced by charge e is: Eext = αħc/2r. (where α is the fine structure constant). Therefore, a sphere with radius r = 10-18 m and charge e would have energy of about 1.2 x 10-10 J in its electric field. An electron’s annihilation energy is about 8 x 10-14 J. Therefore, assuming the electric field equation applies down to 10-18 m, the energy in an electron’s electric field would be about 1400 times more energy than an electron’s annihilation energy. The explanation usually given is that vacuum polarization becomes dominate for the large electric field generated by charge e with small radius. This sounds good if the electron was the only charge e particle. However, a proton has positive charge e and radius of about 9 x 10-16 m. Using the previous equation, the implied energy in a proton’s electric field external to the proton radius is about 10-13 J. This is about 1.6 times more energy than an electron’s annihilation energy but about 0.1% of the proton’s annihilation energy. Therefore, the vacuum polarization does not seem to affect the proton’s electric field. The magnitude of the proton’s charge exactly matches the magnitude of the electron’s charge. If vacuum polarization is assumed to be a factor in determining the macroscopic charge, the effect of vacuum polarization must be exactly calibrated to match these two charges.
I propose this problem is caused by the point particle model of an electron. There is a proposed physical model of an electron which incorporates a single universal field which generates all the other fields of the standard model. An electron is an “excitation” of this universal field. Details of this electron model are given in the referenced paper below. There are two ways of determining the radius of this model. Since a Planck length distortion of spacetime is undetectable, this electron model has undetectable radius. However, this Planck length distortion is a rotating wave (spherical vortex) distributed over a volume with mathematical radius equal to an electron’s reduced Compton wavelength ≈ 3.86 x 10-13 m. Using this larger radius, the electron’s electric field energy external to this larger radius is about α/2 ≈ 0.4% times an electron’s annihilation energy.
What do you think? Other explanations incorporate extra dimensions or merely considering it a mystery beyond human understanding.
Relevant answer
Answer
Stellan,
I looked at your reference up to about page 16. I did not find anything that could answer the question. Can you state a specific percentage or give a page number which contains the answer?
John
  • asked a question related to Two Way
Question
16 answers
Hello everyone,
I would like to receive information and exchange opinions concerning the correct use of analysis of variance in a certain experimental design.
The reason why I'm starting this discussion is that I've found on the internet:
  • -how to perform ANOVA (One way, Two way, Repeated measures, Two-Way repeated measures, Three-way...)
  • -definitions and explanations of experimental designs (Completely randomized, Completely Randomized Block, Split Plot...)
  • many tutorials on different programs (R, SPSS, JMP...)
However, I never found any example or clear explanation on how to perform a Repeated measure ANOVA in a Completely Randomized Block Desing. So either that's a not a very common situation (indeed in agricultural studies it is) or perhaps Blocks cannot be used within the model. I've found some documents (mainly ppt slides) which seem to clearly divide experimental design with blocks and ones with repeated measures, but again, I'm not sure that one doesn't preclude the other.
______________________________________
If that helps, I will provide a short description of one of my field-trial:
  • I'm measuring soil Co2 Efflux (the dependent variable) every two weeks for 3 years (Time --> Repeated measure needed)
  • from a grassland treated with 3 different mowing regimes (N = 3+ treatment --> ANOVA)
  • Such grassland is on a slope (gradient --> we used block design)
______________________________________
Simply put: Since it's a RM-ANOVA am I allowed to not consider the block effect? And what If the measurements of Co2 Efflux were not repeated over time? Then blocks must be considered?
Thank you
Relevant answer
Answer
dear Matteo Francioni , in field experiments where you measured a trait e.g. CO2 emission) more than one and likely more than 3-5 times in each plot, plot is indeed a subject even if per time you have just one measurement per plot. I'm arguing that you actually imposed the plot as a subject (e.g. in SAS, you can do it by the subject statement in GLM and mixed models and by the random statement in Glimmix models).
So block is neither a within-subject, nor a between-subject factor. They are the subject (and are at the same time random), not a factor, nor the levels of a factors
The amount of degrees of freedom needed does not actually depend on the model, but on the amount of total treatments and interactions (and random factors, too). Indeed, if your experiment is quite complex (many treatments with many levels, each and few replicates and pseudoreplicates) you may inadvertently drain all the degrees of freedom for both the fixed factor and interactions and the the random factors, if any, and this would leave you with no DF for the residual error.
This can occur in complex experiments, especially with time-treatments. In such a conditions, you need to collapse some random factor in the total error. By doing so, you will lose power of the analysis, but indeed will be able to estimate the chance your outcomes are somehow depending on your treatments.
Also, the more complex the experiments, the most needed an estimation of the DFs rather than they computations. Usually we use Kenward-Roger approximations for the DF for datasets with n<2000 and Satterthwaite for n>2000.
Lastly, please take into account that if your dataset is unbalanced or its distribution (and distributions by treatment) are not close to the gaussian, separation of means in treatments needs a correction for the distribution. In such a case, I suggest you to use a Tukey-Kramer correction for qualitative data and a Malahanobis distance for multivariate analyses.
I recently published a paper including the SAS pipeline used in the supplementary material. Feel free of catching a look at it and contact me if you need further assistance. The pipeline should also work on JMP but I guess it can be re-computed for SPSS, too.
Please mind that that pipeline has a treatment that is at the one time fixed and random.
Cheers.
Sergio
Saia et al. 2020 Growth-promoting bacteria and arbuscular mycorrhizal fungi differentially benefit tomato and corn depending upon the supplied form of phosphorus. Mycorrhiza DOI: 10.1007/s00572-019-00927-w
  • asked a question related to Two Way
Question
3 answers
Question is not available.
Relevant answer
Answer
Hello Esra,
I noticed that your four questions do not include two of the IVs (candidate status and experimental condition). In light of this, I agree with David Eugene Booth 's suggestion that OLS regression might be a simpler, straightforward solution.
To determine if a given "covariate/IV" does or doesn't help explain differences on the dependent variable (given the others in the model), just look at the test of the four individual regression coefficients (these will be posted as t-tests in spss regression output).
If you elect to run the ancova as described in your query, the relevant tests are for the IVs you mention. The covariates (ed_level, etc.) will each yield a 1 df F-test, and the lone IV that is part of your four questions (time/pressure) will also yield a 1 df F-test.
Good luck with your work.
  • asked a question related to Two Way
Question
3 answers
Question is not available.
Relevant answer
Answer
In my opinion, you should first run a 3-way ANOVA, with 3 Between factors:
1. Social Pressure : 2 levels :yes/no
2. Prime: 4 levels: both, ethnic, personal objectivity, none
3. Ethnicity of Candidate: 2 levels: Western vs Non-Western.
Did you predict a 3-way interaction? You probably did, since you manipulated 3 factors.
When this global ANOVA yields a significant 3-way , you can further refine the analyses according to your predictions.
  • asked a question related to Two Way
Question
3 answers
Hi All, I am currently comparing the EEG funcional connectivity measured at 14 electrodes and 4 frequency bands between highly and lowly hypnotic susceptible individuals. I extracted the coherence and the absolute imaginary coherency for all 91 possible connections. As a design for statistical analysis, I chose a two way repeated measures anova. With the within subject variable Condition(no hypnosis, hypnosis) and the between subject variables Group(highly susceptible (7), lowly susceptible (9)) and Connection(different connections between the electrodes(91)).
Unfortunately I am far from meeting the requirements for normality and equality of error variances. Even with ln(x+1), log(x+1), sqrt(x), 1/x transformation.
Does anyone have an idea, which design of non-parametric tests would fit here?
In the foto you can see the structure of my data set for one frequency band.
Any help would be greatly appreciated.
Many thanks.
Relevant answer
Answer
There are non-parametric alternatives for your Between x Within design.
You can use an aligned ranks test such as the ARTool. This is a factorial repeated measures ANOVA on the aligned ranks. See: http://depts.washington.edu/ilab/proj/art/index.html
There is also the f1_LD_F1 test which is part of the R package nparLD or the f1_LD_f1 SAS macro. See attachments. Shah & Madden explain and illustrate the method underlying the nparLD method.
Luepsen has also developed an R script art3.anova, which is relevant here.
You could also use the ART R package: https://cran.r-project.org/web/packages/ART/ART.pdf
  • asked a question related to Two Way
Question
4 answers
Universities impact the society in many ways. Training , research and service functions are amongst others. However, I am interested to find a theory or a model that best explains the two way impact of the service function of universities. By two way I am referring to the mutual benefits of the service functions.
Relevant answer
Answer
Nigusse Weldemariam Reda thinking about the pathways of impact - how the university would be expected to impact the community, such as academic, economic and social impact https://www.ukri.org/innovation/excellence-with-impact/pathways-to-impact/
With that information, it is possible to measure or explain the impact.
  • asked a question related to Two Way
Question
4 answers
I Want to establish two way relationship between two variable of my model.... is it possible to do so with process macro or simple linear regression is sufficient?
Relevant answer
Answer
Yes
  • asked a question related to Two Way
Question
2 answers
I made a falling-ball model using 6DOF in Fluent.
I tried two ways to define the properties of the ball:
1. UDF:
Mass was defined. Ixx, Iyy, Izz and other properties were not mentioned
2. Options->Six DOF(checked) and implicit update(checked)->Settings...:
Create a property giving mass and all value of Inertia Tensor are 0.
Either way would result in an message when calculating:
Info: 6DOF: can't compute angular acceleration.
Check moments/products of inertia.
I don't know what happened.
The moments/products of inertia are calculated by Fluent solver.
The value was not given in the first method, but the value are 0 initially in the second method.
Why does it said "6DOF: can't compute angular acceleration."? 
Relevant answer
Answer
This has nothing to do with implicit update. You need to specify inertia tensor to compute the angular acceleration.
  • asked a question related to Two Way
Question
2 answers
I need analysis the ergodic achievable rate in paper " Exploiting Full-Duplex Two-Way Relay Cooperative Non-Orthogonal Multiple Access ". i'm using Matlab 2016a.
analytical base on (33) (34) (35) (36) in paper attach
Relevant answer
Answer
Perhaps this article is able to provide some insights about the exponential integral function:
  • asked a question related to Two Way
Question
2 answers
My current experimental design involves several factors (e.g. Treatment, Enclosure, Night and Round), and involving all of them in a multi-factorial ANOVA would result in a large number of interactions. Should I conduct some one-way ANOVA first to drop some unsignificant factors prior to the multi-factorial ANOVA? Is it reasonable to restrict the interactions to two-ways? Many thanks for your attention.
Relevant answer
Answer
The trouble with dropping factors with 1-way ANOVAs is that these factors may not be relevant by themselves but may become relevant when combined with other variables in a multi-way ANOVA. If such is the case, this is a an important result in itself.
My suggestion is to fit a multi-way ANOVA, make sure its assumptions are satisfied, test for significance, remove all the non-significant factors and the non-significant interactions, create interaction plots for the remaining significant interactions (examples here: https://statisticsbyjim.com/regression/interaction-effects/), and finally apply pair-wise tests without p-value adjustment (justification here: ).
  • asked a question related to Two Way
Question
4 answers
This question is about a reviewer’s comment on a paper that I sent to an appropriate journal. I first describe the research in the paper. It had three research questions. The first question asked whether an intervention affects significantly the outcome (dependent) variable. To answer the first research question, we ran ANCOVA test that takes into consideration the differences of students’ scores before the experiment in the three participating classes. We did that, though we had taken account of these differences by running ANOVA for the scores of the three classes before the experiment. In addition, when getting significant differences, to find out which pairs of groups differ significantly, we ran Scheffe post hoc analysis.
The second and third research question asked whether the interaction of the intervention with gender (two values) and ability (three values) affected significantly the outcome variable. To answer the second and third research questions, we ran two way ANCOVA. The two independent variables, in our case, are the class type (three classes, one experimental and two control) and student’s gender (or ability). The covariate is the value of the outcome variable at the beginning of experiment.
Sending the paper that included the research to an appropriate journal, I received a comment from a reviewer that 2x3 ANCOVAs to test the interactions actually make the one-way ANCOVAs redundant. In addition, the reviewer requested more information about the size of the samples (three samples: one experimental and two control) and cell requirements for your analyses (2x3 and 3x3). The reviewer said that the sample sizes meet the 10 subjects per cell statistical requirement, but likely put the robustness of the 3x3 analyses in question. Can anybody explain the reviewer’s comments please? Why 2x3 ANCOVAs to test the interactions actually make the one-way ANCOVAs redundant? How to compute the robustness of the analysis? What is the importance of this robustness?
Relevant answer
Answer
Hello Wajeeh,
It seems to me that all three questions are answerable from a single analysis: a 3 (class, which apparently is the treatment dimension) x 2 (gender) x 3 (ability) ancova (where, we presume, some sort of baseline score is the covariate). Since you didn't indicate sample size, it's impossible to comment on whether cell size is adequate (and, for the record, a blanket assertion by reviewer that 10/cell is sufficient, could be wildly misleading).
This set-up lets you test:
1. main effect of class (question 1), holding other effects constant
2. class x gender interaction (question 2), holding other effects constant
3. class x ability interaction (question 3)....
4. gender x ability interaction (even though you don't declare that as a question...
5. class x gender x ability interaction (even though...)
6. main effects of gender and ability, holding other effects constant
In this framework, the ancova (and anova) for the sole effect of class is redundant with that of the full, 3-way model analysis.
Good luck with your work!
  • asked a question related to Two Way
Question
4 answers
Hi, I want to prepare a Ag/AgCl electrode as reference electrode(commercial ones are too large for my test..) with a silver wire (0.01 inch)
1 Leave it in bleach for 30 minutes ;
2 Electrolytic deposition in 0.1M HCL solution ;
Can this two ways work?
Can anyone give me some papers about preparation of Ag/AgCl electrode?
Thanks.
Relevant answer
Answer
Thank you Kenneth! It's very helpful!
  • asked a question related to Two Way
Question
10 answers
Hi there,
The data I am analysing is temperature data inside nest boxes. There are 2 factors, aspect (North or South) and treatments (insulated or uninsulated). There are 92 nest boxes and 90 days worth of temperature data. With such a large dataset it violates the assumptions. Is there a good alternative in SPSS?
Cheers!
Relevant answer
Answer
You probably should aggregate the daily temperature data (mean, median, ..) for each nest. I guess you are not interested in a temperature change between two days, so an average value could be better for comparison.
On the other hand, if daily changes are important for your study, you should use a base value of environment temperature as a covariate to control the variance for weather effects.
  • asked a question related to Two Way
Question
4 answers
Hi. In R l used the mixed-effects model and found a tsignificant hree-way interaction between working memory (as a continuous variable), syntactic position (subject position v.s. object position) and ambiguity type (ambiguous v.s. unambiguous). The dependent variable is reading time. Then I looked into the two way interaction between working memory and ambiguity type for each syntactic position but none of the tests reached significance. Does this mean the way I did the follow-up test was not right? Is there any other way to conduct a follow-up test for a three-way interaction in a design like this?
Thank you in advance.
Relevant answer
Answer
Thank you so much for this. I will have a look.