Inconsistent results in bayesian t-tests using residuals of co-variates
Dear JASP community,
I would like to ask your help with the following problem for my analysis in JASP.
I performed Informed Independent Bayesian Student t-tests using residuals of a linear regression to control for co-variates (age, sex, education) and set the location of the prior at -0.7 and scale at 0.707 to test my Hp that group 1< group 2.
I obtained the same Bayes factor number for all the variables (Screenshot 1), despite these variables had different distributions (Screenshot 2).
When I performed a Mann-Whitney t-test for not normally distributed data, I got then different Bayes factor numbers for each variable of interest (Screenshot 3).
The fact that my data are not normally distributed may be the reason why I get these strange results with Student t-test? Should I then take for reliable the results obtained from the Mann-Whitney t-test?
I would be super grateful if someone could help me understand the issue.
Thank you in advance.
Best regards,
Alice
Screenshot 1
Screenshot 2
Screenshot 3
Comments
This just looks like a bug. If you enter the variables individually you should see different results. I will try to see if I can reproduce this...no, it works fine for me, I get different results. Please post the issue on our GitHub page, and outline a clear reproducible path (for details see https://jasp-stats.org/2018/03/29/request-feature-report-bug-jasp/). This would help us a lot.