Is it possible to conduct a MANCOVA with a dummy coded DV in the variate? I have 5 DVs, and 2 of them are extremely skewed (# suspensions and # schools attended in one school year—as you can imagine, the norm is 0 and 1 respectively). I am using a 1/x transformation, but that makes interpretation so much harder! Tabachnik speaks of trying sqrt, LG10, and 1/x transformations, and if all else fails, dichotomize. I know a dummy coded variable works as a predictor in linear regression, and MANCOVA is just sorta doing that backwards, but when I google it, I’m seeing people saying that using a binary variable violates the assumptions of normal distribution and equal variances. So I think I’m convinced I have to transform... even though the distribution is still skewed, it’s dramatically better. I have an IV with three categories, and 5 covariates. The n for the 3 groups is 201, 250 and 363 respectively. Thanks in advance for your advice!
Is it possible to conduct a MANCOVA with a dummy coded DV in the variate? I have 5 DVs, and 2 of them are extremely skewed (# suspensions and # schools attended in one school year—as you can imagine, the norm is 0 and 1 respectively). I am using a 1/x transformation, but that makes interpretation so much harder! Tabachnik speaks of trying sqrt, LG10, and 1/x transformations, and if all else fails, dichotomize. I know a dummy coded variable works as a predictor in linear regression, and MANCOVA is just sorta doing that backwards, but when I google it, I’m seeing people saying that using a binary variable violates the assumptions of normal distribution and equal variances. So I think I’m convinced I have to transform... even though the distribution is still skewed, it’s dramatically better. I have an IV with three categories, and 5 covariates. The n for the 3 groups is 201, 250 and 363 respectively. Thanks in advance for your advice!