We are running a learning experiment with a between-subjects design on alpine skiing: one group training according to an interleaved schedule whereas the other group train according to a blocked schedule. We have measured the skiers' performance on the same courses on the pre and post-test.
The population has a hierarchical structure; that is, we sample ski groups of (5-12) that belong to a ski academy. And we randomly allocate these skiers into the two groups: interleaved and blocked.
I thought running an ancova model where I predict the post-test would be appropriate for this situation
Post-test = b0 + b1×pretest + b2×group
However, I also think it would be interesting to use a linear mixed-effect model where we predict the post-test and include a random intercept and slope for each skier.
post-test ~ time * group + (1|skier)
Perhaps also for include ski academies as a fixed or random effect
post-test ~ time * group + skiacademy + (1|skier)
I do not have much experience with these linear mixed models and I don't know if it would be a simple pre and post-test experiment? I appreciate your help.
(We are aiming to recruit a total of 100 alpine skiers and so far we have tested 40 skiers)