# JASP newbie: pre-post with unequal number of observations

I have a study in which my 10 participants perform a task 90 times in each of two conditions. Being human, sometimes they make mistakes, so for a particular participant, I could have a different number of observations in each condition.

i believe this requires a linear mixed model, but I don’t know how to set it up in JASP. Given its wide data format, some rows will have empty values. (Edit: is there an easy long to wide converter?)

I’ll also need to account for each participant’s preferred speed in doing the task, which I think would mean a nuisance variable for participant.

Would greatly appreciate any pointers or suggestions!

## Comments

Hi JohnAtl,

We are currently working on including linear mixed models, but we're not quite there yet. With 90 trials (I assume 45 per condition), I would be amazed if your conclusions depend on the unequal data sizes. So I am going to be rebellious and predict that if you t-test the subjects' mean outcomes in the two conditions you'll get an answer that is very very close to whatever you get from your linear mixed model.

Cheers,

E.J.