I have a data set of repeated measures, but I do not have multiple groups (in other words, I am only interested in an effect of time, no other variables or interaction). When I run the Linear mixed effects without a group category, I receive an error saying that this value is missing. Is there a way to run this analysis only looking for an effect of time? Thanks!
Are you using gneiss or longitudinal? I’m guessing the latter, but both have methods dealing with linear mixed effects. Could you provide the command you ran and the error you received? Thanks!