Musicians' health literacy: Setting guidelines

I am reviewing some work where the researcher has performed the Pearsons R test using 6 cases. The sample size certainly 'feels' too small for this to be a valid test, however unlike other tests (Spearmans, Kendalls) where the texts clearly identify the minimum sample size necessary to perform a valid test I can find no such number for Pearsons R, hence the need for this question. 

Any thoughts?

Dear colleagues, 

I am uncertain about choosing appropriate statistics test (by using SPSS) to measure the effectiveness of an intervention applied in my academic writing classroom. In particular, my investigation is designed in the model of pre/post test single group. This means the data were collected in two periods: before and after applying the intervention. The problems are (i)  this study was conducted on only one single group using the same set of questionnaire at two different periods. (ii) The data include multi-dependent variables (different aspects of one dependent variable) and one independent variable ( a specific method used to examine its effectiveness).

How can I run a test in SPSS to measure the impact of one independent variable on various dependent variables in this case? 

I use nonparametric tests due to small groups and the absence of normal distribution. For Mann-Whitney U test I calculate the effect size by dividing U with the product of the two group sizes (as suggested by Ronán M. Conroy as well as others).

How do I most appropriately calculate effect size for Wilcoxon signed rank test (related samples)? 

I believe Cohen's d is not appropriate since it requires normal distribution and is based on means, hence the alternative effect size above for M-W U. Agree?

I am writing my master thesis and I want to see if showing a red picture activates "danger" mental state, while if showing a blue pictures keeps them at relaxed state. So I want to see if there are differences in mental states between the two groups and if "danger" group will be more anxious.

I thought of two options:

1) Measuring how stressed they are after seeing the picture

2) Make associations test with pre-determined options to select from: one which is more danger related, another which is more neutral.

The problem with (1) is that it might not capture the actual change in anxiety and it can be very subjective to how they were feeling even before they started the survey.

The problem with (2) is that it is very subjective and might capture only already established associations and not really due to the treatment. It is also subjective to my perception of words that are more "danger" and "neutral".

What can I do to measure for this small shift in the mind set?

Thank you.

I'm looking for people with an interest in developing interventions aimed at increasing health literacy that would be part of the higher education curriculum.

Are you superstitious?

If the scientist can be superstitious or can he have respect for superstitions?

Can a scientist completely ignore superstitions if he does not research them scientifically?

Are superstitions an atavistic element of culture?

Are they atavistic remnants of the ancient times when people have explained the occurrence of puzzling, unrecognized scientific atmospheric, climatic, cosmic phenomena, etc., explaining this by the action of higher, supernatural forces, etc.?

Please reply

I invite you to the discussion

Thank you very much

Best wishes