# How does JASP calculate the confidence interval for Cohen's d in Welch's t test for 2 ind vars?

*have _been able to replicate confidence interval results for _Student's t test* by finding the non centrality parameter of the t distribution using Rs numerical uniroot method and Bonett's method. I can supply code and data on application. Also if you can give a reference for your formula as I have been unable to find an explanation of the method for this test. Thanks.

## Comments

Dear JASPUser,

I would have to ask the team member responsible for this, or you could check our code, but it seems to me that "t.test" in R uses the Welch test by default ("var.equal = FALSE"). You could check their documentation for details.

Cheers,

E.J.