hello!

I am running a mixed effects analysis on Jamovi using GAMLj. I have2 continuous covariates and 1 categorical factor (with 4 levels), with all main effects and 2-and 3-way interaction terms as fixed effects (on slope) and subjects as random effects (on intercept) in my model. I have a significant interaction between my categorical factor and one of my continuous covariates on my DV. I want to get to know in which levels of my factor the effect of my covariate on my DV changes, with simple effects. I put my categorical factor as moderator and my covariate as simple effects variable. However, both simple effects and post hoc return infinite num and den dfs, and thus do not compute the t-stats (and F-stats). my number of observations is 6069.

Why do both post-hoc and simple effects return infitine dfs? how can I overcome this problem?

thanks so much in advance,

tutku