Firstly, I have a randomized crossover study to analyse and my first question is does the nature of a crossover study (n= 10 or n=30 depending on how you look at it) mean I should do anything different form a normal RCT?

Secondly, the only tutorial I have been given told me to analyse normality for the whole column (e.g. pre-test bodyweight. However a textbook I have (by Andy Field) says you should split the data into groups then test normality. Which way is correct?

Thirdly, if my pre-test data is normally distributed but the corresponding post-test column is non-normal, when I want to test repeated measures, should I transform the data, use a non-parametric test, or do something else?

fourthly, my text book 'the spss survival guide' says ANOVA is robust enough to mean you can ignore violations of normality if the sample size is over 30. my sample size is exactly 30 (though it is a crossover with 10 subjects undergoing all 3 conditions so 10 X 3 = 30). should i just ignore that i have non-normal data and use a mixed between-within ANOVA to test for interaction effects?

Please help!!!!!