I want to know whether the intervention would make a significant change to the participant or not by assessing:

(i) the difference in pre-test and post-test for each cycle,

(ii) the difference in the post-tests (cycle 1 & cycle 2)

(iii) the increment of scores between the different cycles

What would be the suitable way to analyse the data here? As far as I know, it's either paired t-test or Wilcoxon signed rank test, and it would usually depend on whether there is a normal distribution or not. However, I am not sure if I still have to do normality test since I only have one participant. I have also read that the minimum sample for Shapiro-Wilk normality test is 3. If I just use Wilcoxon signed rank test instead of paired t-test, I would have to give justification on why.

Thank you and any insights would be helpful.