Hi all, Quick summary: (How) can I perform multiple regression analysis with a very strongly positively skewed variable, ideally using SPSS? Details: I have a dataset comprised of 206 participants been recruited on the basis that, where faced with a choice between Option A or Option B only, they almost always choose Option A not B. The study aims to predict why they might (occasionally) choose Option B not A. The outcome variable is the % of times over a 2-week period that Option B not A was chosen (i.e. % = number of option B choices / number of choice opportunities). Frequencies indicate that 87% of participants chose Option A on 100% of occasions. 5% of participants chose Option B not A on 10% of occasions. Only 1% chose Option B not A on the majority of occasions. I have a number of potential predictor/explanatory variables that I would like to test as predictors of participants’ deviation from using Option A all of the time. Can such an analysis be meaningfully conducted (using SPSS) with such heavy positive skew? If so, how? (NB - using base 10 logarithm doesn’t work - the skewness Z score, which I understand should be less than 1.96, is 35.21, and the base 10 log reduces it only to 14.55.) Thanks, Ben Gardner