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Introduction

**Skills and Expertise**

## Publications

Publications (295)

Regression coefficients are crucial in the sciences, as researchers use them to determine which independent variables best explain the dependent variable. However, researchers obtain regression coefficients from data samples and wish to generalize to populations; without reason to believe that sample regression coefficients are good estimates of co...

The use of theory in health behavior change interventions has been recently questioned with mixed results found for theory-based intervention effectiveness. But theory testing in intervention depends on not only theoretical assumptions, but on auxiliary assumptions too. Specifically, auxiliary assumptions are required to traverse the distance from...

There is a growing statistical literature pertaining to how researchers can make specifications for precision and confidence, with a priori procedure (APP) equations providing the necessary sample size to meet those specifications. However, an important limitation of that literature is that there are no APP equations pertaining to estimating parame...

Much research in the economics and social sciences is based on nonmeaningful units. A consequence is that substantive researchers often have difficulty in interpreting their data. If there is a one-point difference between the means in two conditions on, say, subjective well-being, it need not be clear how to interpret that difference. In addition,...

Marketing scholars often compare groups that occur naturally (e.g., socioeconomic status) or due to random assignment of participants to study conditions. These scholars often report group means, standard deviations, and effect sizes. Although such summary information can be helpful, it can misinform marketing practitioners’ decisions. To avoid thi...

Consumer autonomy is a fundamental topic for marketing ethics scholars. Nonetheless, autonomy’s philosophical treatment may have compromised its conceptual clarity. After reviewing the relevant ethics literature on consumer autonomy, the benefits of formally defining consumer autonomy are illustrated, and a novel formalization is adapted from poten...

Although the literature on the a priori procedure, designed to help researchers determine the sample sizes they should use in their substantive research, is expanding rapidly, there are two important limitations. First, there is a need to expand to new popular distributions, log-normal and gamma distributions, and the present work provides those ex...

The vast majority of empirical hypotheses in psychology, or in the social sciences more generally, are directional whereas in other sciences, such as the physical sciences, there are more point or narrow‐interval empirical hypotheses. Characteristics of theories and auxiliary assumptions play a role in the difference. Given that psychology research...

Marketing scholars often compare groups that occur naturally (e.g., socioeconomic status) or due to random assignment of participants to study conditions. These scholars often report group means, standard deviations, and effect sizes. Although such summary information can be helpful, it can misinform marketing practitioners’ decisions. To avoid thi...

The a priori procedure (APP) is concerned with determining appropriate sample sizes to ensure that sample statistics to be obtained are likely to be good estimates of corresponding population parameters. Previous APP work pertaining to proportions has used the normal approximation to the binomial distribution, but this is problematic when the popul...

Background
Null Hypothesis Significance Testing (NHST) is the most familiar statistical procedure for making inferences about population effects. Important problems associated with this method have been addressed and various alternatives that overcome these problems have been developed. Despite its many well-documented drawbacks, NHST remains the p...

In the debate about the merits or demerits of null hypothesis significance testing (NHST), authorities on both sides assume that the p value that a researcher computes is based on the null hypothesis or test hypothesis. If the assumption is true, it suggests that there are proper uses for NHST, such as distinguishing between competing directional h...

Purpose
The authors derive the necessary mathematics, provide computer simulations, provide links to free and user-friendly computer programs, and analyze real data sets.
Design/methodology/approach
Cohen's d , which indexes the difference in means in standard deviation units, is the most popular effect size measure in the social sciences and econ...

There is an increasing trend for researchers in the social sciences to draw causal conclusions from correlational data. Even researchers who use relatively causally neutral language in describing their findings, imply causation by including diagrams with arrows. Moreover, they typically make recommendations for intervention or other applications in...

Perfect duties are those required by moral individuals, whereas imperfect duties, although not required, are expected of moral individuals. Previous research suggests it takes fewer perfect than imperfect duty violations to override an existing impression of a person as moral. Presently, we examine moral attributions about immoral people performing...

The research to be presented concerns estimating the probability that a randomly selected person from one population will score better than a randomly selected person from another population, and by how much. Previous mathematics have addressed two skew normal distributions (Tong et al., submitted manuscript). The present work integrates the forego...

Researchers typically assume that they are working from a normal distribution and with independent sampling. Both assumptions are often violated. Our goal was to explore the intersection of the violations: Is the net effect good or bad? Using the family of skew-normal distributions, which is a superset of the family of normal distributions, we test...

There is a long history of discussion about the ability of researchers to generalize their findings. But findings are not the only entity that researchers can attempt to generalize. Scientists have theories, empirical hypotheses, and statistical hypotheses too. The extent to which scientists can generalize these is an open issue. As a prerequisite...

In a recent article, Trafimow suggested the usefulness of imagining an ideal universe where the only difference between original and replication experiments is the operation of randomness. This contrasts with replication in the real universe where systematicity, as well as randomness, creates differences between original and replication experiments...

There have been many criticisms of null hypothesis significance testing (NHST), including important ones made by Dr. Hung Nguyen. The goal of this chapter is to honor Dr. Nguyen for his important scientific contributions by introducing a new argument against NHST that complements the arguments he already has made. Specifically, NHST aficionados som...

The present work constitutes an expansion of the a priori procedure (APP), whereby the researcher makes specifications for precision and confidence and APP equations provide the necessary sample size to meet specifications. Thus far, APP articles have mostly focused on the results of true experiments, where it is possible to randomly assign partici...

Null hypothesis significance testing (NHST) has had and continues to have an adverse effect on marketing research. The most recent American Statistical Association (ASA) statement recognized NHST’s invalidity and thus recommended abandoning it in 2019. Instead of revisiting the ASA’s reasoning, this research note focuses on NHST’s pernicious periph...

It has been asserted that the Theory of Planned Behavior (TPB) is better at behavioral prediction than it is behavioral change. However, the performance of a theory depends not only on the theoretical propositions, but the auxiliary assumptions attached to the theory. It is because of such auxiliary assumptions, which are required to bridge the gap...

There are two main inferential statistical camps in psychology: frequentists and Bayesians. Within the frequentist camp, most researchers support the null hypothesis significance testing procedure but support is growing for using confidence intervals. The Bayesian camp holds a diversity of views that cannot be covered adequately here. Many research...

Confidence intervals (CIs) constitute the most popular alternative to widely criticized null hypothesis significance tests. CIs provide more information than significance tests and lend themselves well to visual displays. Although CIs are no better than significance tests when used solely as significance tests, researchers need not limit themselves...

(Note: For a full copy until 2 June 2020, go to https://authors.elsevier.com/a/1auVAXj-jVZng.)
Knowing related empirical facts as precisely as possible is crucial to knowledge development. Does the sampling precision of published consumer research ensure it contributes meaningfully to marketing science? To answer this question, the sampling precis...

Should mandatory theorizing be a condition for researchers to publish articles? Should more synthesis be required, perhaps with the aid of meta-analysis? This short comment focuses on both questions that arise from Phaf’s article, “Publish less, read more” (2020).

Causal models in organizational research are complex. As use of complex models increases, the joint probability a published model is true decreases. Across The Academy of Management Journal ( AMJ), Organizational Behavior and Human Decision Processes ( OBHDP), and Administrative Science Quarterly ( ASQ) from 2016 to 2018, it was most common to see...

Previous researchers have shown how to compute a priori confidence interval (as opposed to sample-based confidence intervals) for means, assuming normal distributions (Trafimow 2017 Trafimow, D. 2017. Using the coefficient of confidence to make the philosophical switch from a posteriori to a priori inferential statistics. Educational and Psychologi...

There has been much debate about null hypothesis significance testing, p-values without null hypothesis significance testing, and confidence intervals. The first major section of the present article addresses some of the main reasons these procedures are problematic. The conclusion is that none of them are satisfactory. However, there is a new proc...

Previous researchers have proposed the a priori procedure, whereby the researcher specifies, prior to data collection, how closely she wishes the sample means to approach corresponding population means, and the degree of confidence of meeting the specification. However, an important limitation of previous research is that researchers sometimes are...

Despite wide acceptance that replications across operationalizations and contexts is positive for psychology, the present goal is to suggest a more nuanced view that sometimes successful replications can be to the detriment of progress in psychology. The present manuscript distinguishes between replication in two idealized universes. In one such un...

Although the null hypothesis significance testing procedure is problematic, many still favor the use of p-values as indicating the state of evidence against the model used to generate the p-value. From this perspective, p-values benefit science; or would benefit science if used correctly. In contrast, the novel argument to be presented introduces a...

The American Statistical Association’s Symposium on Statistical Inference (SSI) included a session on how editorial practices should change in a universe no longer dominated by null hypothesis significance testing (NHST). The underlying assumptions were first, that NHST is problematic; and second, that editorial practices really should change. The...

Statistical inference often fails to replicate. One reason is that many results may be selected for drawing inference because some threshold of a statistic like the P-value was crossed, leading to biased reported effect sizes. Nonetheless, considerable non-replication is to be expected even without selective reporting, and generalizations from sing...

Based on the banning of null hypothesis significance testing and confidence intervals in Basic and Applied Psychology (2015), this presentation focusses on alternative ways for researchers to think about inference. One section reviews literature on the a priori procedure. The basic idea, here, is that researchers can perform much inferential work b...

Classical hypothesis testing, whether with p-values or Bayes factors, leads to over-certainty, and produces the false idea that causes have been identified via statistical methods. The limitations and abuses of in particular p-values are so well known and by now so egregious, that a new method is badly in need. We propose returning to an old idea,...

The journal, Basic and Applied Social Psychology, banned null hypothesis significance testing and confidence intervals. Was this justified, and if so, why? I address these questions with a focus on the different types of assumptions that compose the models on which p-values and confidence intervals are based. For the computation of p-values, in add...

In this paper, the desired sample size for estimating the skewness parameter with given closeness and confidence level under skew normal populations. The confidence intervals for skewness parameter are constructed based on the desired sample sizes using two pivots, chi-square distribution and F-distribution. Computer simulations support our main re...

After obtaining a sample of published, peer-reviewed articles from journals with high and low impact factors in social, cognitive, neuro-, developmental, and clinical psychology, we used a priori equations recently derived by Trafimow (Educational and Psychological Measurement, 77, 831–854, 2017; Trafimow & MacDonald in Educational and Psychologica...

Statistical inference often fails to replicate. One reason is that many results may be selected for drawing inference because some threshold of a statistic like the P-value was crossed, leading to biased reported effect sizes. Nonetheless, considerable non-replication is to be expected even without selective reporting, and generalizations from sing...

Statistical inference often fails to replicate. One reason is that many results may be selected for drawing inference because some threshold of a statistic like the P-value was crossed, leading to biased reported effect sizes. Nonetheless, considerable non-replication is to be expected even without selective reporting, and generalizations from sing...

According to standard experimental practice, researchers randomly assign participants to experimental and control conditions, deeming the experiment “successful” if the means of the two conditions differ in the hypothesized direction. Even for complex experiments, with many conditions, success generally depends on a comparison or contrast of means...

Although it is well-known that confidence intervals fail to provide the probability that the population parameter of interest is within the computed interval, there nevertheless continues to be widespread support for them. Such support is based on the argument that confidence intervals measure precision; wide intervals indicate less precision where...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance tes...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance tes...

Possibly, the replication crisis constitutes the most important problem in psychology. It calls into question whether psychology is a science. Existing conceptualizations of replicability depend on effect sizes; the larger the population effect size, the greater the probability of replication. This is problematic and contributes to the replication...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significan...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science.
Given that blanket and variable alpha levels both are problematic, it is sensible to dispense
with significan...

We argue that making accept/reject decisions on scientiﬁc hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the ﬁnding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense
with signiﬁcance...

There is a massive crisis of confidence in statistical inference, which has largely been attributed to overemphasis on and abuse of hypothesis testing. Much of the abuse stems from failure to recognize that statistical tests not only test hypotheses, but countless assumptions and the entire environment in which research takes place. Unedited and un...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance tes...

Two recent publications in Educational and Psychological Measurement advocated that researchers consider using the a priori procedure. According to this procedure, the researcher specifies, prior to data collection, how close she wishes her sample mean(s) to be to the corresponding population mean(s), and the desired probability of being that close...

It is widely accepted that habits are automatic. In turn, automaticity often has been taken as implying (a) a lack of use of resources, (b) inevitability, and (c) a lack of intentions. All three characteristics of automaticity create conceptual difficulties, at least in the context of habits. Inconvenient questions arise from a careful consideratio...

Evolutionary theory was applied to Reeder and Brewer's schematic theory and Trafimow's affect theory to extend this area of research with five new predictions involving affect and ability attributions, comparing morality and ability attributions, gender differences, and reaction times for affect and attribution ratings. The design included a 2 (Tra...

We argue that depending on p-values to reject null hypotheses, including a recent call for changing the canonical alpha level for statistical significance from .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable criterion levels both are problematic, it is sensible to dispense...

The notion of Socratic Note Taking (SNT) is introduced to enhance students' learning from assigned readings. SNT features students asking questions and answering their own questions while doing the readings. To test the effectiveness of SNT, half the students from two sections of a philosophy course were assigned SNT on alternating weeks. Quizzes e...

Teachers who offer undergraduate courses agree widely on the importance of writing assignments to further undergraduate education. And yet, there is a great deal of variance among teachers in their writing assignments; some teachers assign no writing whatsoever. To determine the variables that influence the decisions of teachers about whether to as...

An important problem with null hypothesis significance testing, as it is normally performed, is that it is uninformative to reject a point null hypothesis [1]. A way around this problem is to use range null hypotheses [2]. But the use of range null hypotheses also is problematic. Aside from the usual issues of whether null hypothesis significance t...

This commentary on Jussim (2012) makes two points: (1) Effect sizes often reflect artifacts of experimental design rather than real-world relevance, and (2) any argument dependent on effect sizes must correct for attenuation due to instrument reliabilities. A formula for making this correction is presented, and its ramifications on the debate over...

Because error variance alternatively can be considered to be the sum of systematic variance associated with unknown variables and randomness, a tripartite assumption is proposed that total variance in the dependent variable can be partitioned into three variance components. These are variance in the dependent variable that is explained by the indep...

Although many common uses of p-values for making statistical inferences in contemporary scientific research have been shown to be invalid, no one, to our knowledge, has adequately assessed the main original justification for their use, which is that they can help to control the Type I error rate (Neyman & Pearson, 1928; 1933). We address this issue...

Psychologists take two propositions for granted. Specifically, empirical verification of predictions derived from a theory (a) support that the theory is more likely to be true and (b) support that additional predictions derived from the theory have an increased probability of being sustained if subjected to empirical testing. In contrast, I argue...

There has been much controversy over the null hypothesis significance testing procedure, with much of the criticism centered on the problem of inverse inference. Specifically, p gives the probability of the finding (or one more extreme) given the null hypothesis, whereas the null hypothesis significance testing procedure involves drawing a conclusi...

Past research on short-term memory decay has found that participants are more efficient at remembering information when the delay between stimuli presentation and recall is short as opposed to long. In the current study we used Potential Performance Theory (PPT) to identify the role that both random and systematic factors play in observed memory pe...

Klein (2014) argues that the replication crisis in social psychology is due—at least in large part —to the tendency of psychological theories to be ill-specified. We disagree. First, we use both historical and contemporary examples to show that high-quality replication is possible even in the absence of a well-specified theory; and, second, we argu...

The selection of field experiment locations often requires that the control location be comparable to the treatment location. Recently, a method that employs the mathematics of potential performance theory was proposed for comparing field experiment locations by parsing random versus systematic effects. Here, we apply this method to archival data (...

Typically, in education and psychology research, the investigator collects data and subsequently performs descriptive and inferential statistics. For example, a researcher might compute group means and use the null hypothesis significance testing procedure to draw conclusions about the populations from which the groups were drawn. We propose an alt...

Complex causal models, accompanied by causal analyses based on large correlation matrices, are more common in the social sciences than are simple causal models accompanied by a single correlation coefficient. The increased complexity of the former, relative to the latter, seems to carry with it an augmented scientific respectability or credibility....

The intention attribution literature suggests that a success or a failure by a skilled person will result in a large difference in the intentions others will attribute to that person, but that this effect will be attenuated dramatically if the person is unskilled. The received literature is less clear about what to predict for desire attributions o...

We obtain the input data for Bayes Theorem, and use the theorem to determine the probability of a patient having a lumbar HNP, given only a positive MRI. We also enumerate the potential consequences that the clinician must keep in mind when making the diagnosis of lumbar HNP. We used the theorem by Bayes, in conjunction with well-established result...