I have 20 subjects, all subjects received 2 interventions, and i measured outcome 5 times for each intervention, thus, each subject i will have 10 measurements.
Based on qqplot and shapiro-wilk test, i don't think parametric test would be a safe option. I am not so sure which non-parametric test is a good choice, so i decide to go for most general one: linear regression.
In this case, what are my predictor/input variable, and output variable? I assume all measurements for intervention 1 is the output, and all my measurements for intervention 2 is one of the input variable, what is the other input variable? index for each measurement? In addition, what is the relation between two input variables? confounder or interaction?