Hey all,
Ok so I'm trying to compare the means of two sets of data using a 2-sample t-test. Unfortunately, both sets of data are non-normal. It appears box-cox or Johnson transforms will work, but my question is, wouldn't I need to transform both sets of data using the same transform parameters (lambda for BC and the transform function for the Johnson) in order for the comparison to be valid? I would think if I use two different sets of transform parameters than the data would be shifted in differing amounts, potentially spreading out the means (incorrectly??). Hopefully this makes sense! Thanks.
Ok so I'm trying to compare the means of two sets of data using a 2-sample t-test. Unfortunately, both sets of data are non-normal. It appears box-cox or Johnson transforms will work, but my question is, wouldn't I need to transform both sets of data using the same transform parameters (lambda for BC and the transform function for the Johnson) in order for the comparison to be valid? I would think if I use two different sets of transform parameters than the data would be shifted in differing amounts, potentially spreading out the means (incorrectly??). Hopefully this makes sense! Thanks.