strengejacke / esc

Effect Size Computation for Meta Analysis
https://strengejacke.github.io/esc
20 stars 6 forks source link

Standard deviation for the Fisher's z transformation of the correlation coefficient #8

Open tqtbui opened 3 years ago

tqtbui commented 3 years ago

Hello,

Thank you very much for the nice package. I have a question when using the package.

I was using the function esc_mean_sd() to convert means and sds to a point-biserial correlation coefficient. I wonder how the standard deviation for the Fisher's z transformation was calculated.

I learn that the formula is sqrt(1/(n-3)) from here, also from the book "Practical Meta-analysis", but when I double check the output of function esc_mean_sd(), it does not match.

Could you please help me explain why?

Thank you very much! Best regards, Trang Bui.