Comparison of Bayes Factor for correlations calculated in JASP vs. in R using the BayesMed package
I recently tried out JASP to run some Bayesian analyses. So far, I have been using R for this, and I was interested in whether I would get the same results, especially since JASP is using R internally for its analyses.
Computing the Bayes Factors for t-tests in JASP lead to the same results as the ttestBF function from the BayesFactor R package (I think JASP uses this function internally). However, the results were different for correlations. Specifically, I calculated the correlation between Agreeableness and Openness in the Big5 example dataset provided by JASP.
Using JASP Bayesian Correlation Pairs to calculate the Bayes Factor for the correlation (with default settings, i.e. Hypothesis: correlated, Beta*prior width = 1), leads to a BF10 = 32.64.
Calculating the Bayes Factor in R with the following script:
library(BayesMed) dataset <- read.csv("Big 5 (Dolan, Oort, Stoel & Wicherts, 2009).csv",sep=" ") with(dataset,jzs_cor(Agreeableness,Openness,alternative="two.sided"))
leads to a Bayes Factor of 21.01.
I would be very interested in understanding where the different results come from. It would be great if someone could point me to an explanation. Thanks a lot in advance!