Hi R-Sig-mixed-models, My question is about the use of predictions of effects for specific units (such as an individual in the case of repeated measures data) in other models. I'm especially interested in whether the group thinks this is a good / useful approach for using repeated measures data to predict a longer-term outcome. I am also interested in whether the group has any suggestions for betters way to do this (or to combine what now requires two models). For example, were individual-level predicted effects to be obtained from a mixed effects model (through a null model, i.e. there is random intercept for individuals and no fixed effect), could they be used to predict an individual-level outcome? I am thinking about this specifically in the context of repeated measures data (collected using Experience Sampling Method, or ESM, whereby students are asked every so often to respond to questions about their interest and engagement) and pre- and post-survey measures, representing a longer-term outcome, students' self-reported interest in a STEM career. Here is how I am thinking about this, using lmer() and lm() to specify the models: m1 <- lmer(repeated_measures_outcome ~ 1 + (1 | participant), data) Process the data to obtain the predicted intercept for each participant. m2 <- lm(longer_term_outcome ~ prior_level_of_longer_term_outcome + predicted_intercept_for_participant) When I have shared this idea with others (i.e., in this Stack Overflow question) I have received feedback that a) yes, you can do this and b) you could / should combine the two models (m1 and m2 in this example) into one model. This would (obviously?) require using a different approach - but I do not have a clear idea of what this would require (MCMCglmm? brms?). Any general or specific advice is welcomed. Thank you for your consideration of this. If I can or need to provide more detail or background, then please do not hesitate to tell me so! Josh
Joshua Rosenberg, Ph.D. Candidate Educational Psychology & Educational Technology Michigan State University http://jmichaelrosenberg.com [[alternative HTML version deleted]]