David Sidhu posted on Thursday, April 05, 2018 - 3:55 pm
I have a set of 20 items that have each been rated by thirty participants, on 25 dimensions. I am interested in performing factor analysis on those 25 dimensions.
I gather that it would be no problem to conduct a multilevel factor analysis, and account for the fact that observations are nested within participants. But, could I also model the fact that observations are nested within items? Note that subjects and items would be fully crossed random effects, not nested within each other.
David Sidhu posted on Thursday, April 05, 2018 - 6:34 pm
Thanks for getting back to me! I will try that. I realize that I may not have been specifying the random terms correctly. In my attempt to run a model with observations nested within subjects, I did this:
TITLE: exploratory factor analysis DATA: FILE IS wordtriallevelmplus.dat; VARIABLE: NAMES ARE...(removed to save space); USEVARIABLES ARE ...(removed to save space); CLUSTER = PPT; MISSING ARE ALL (999); ANALYSIS: TYPE = TWOLEVEL EFA 1 5 UW 1 5 UB; OUTPUT: MODINDICES;
Did I also need to add the extra bits you did for the MODEL? I.e., also add:
MODEL: %WITHIN% f BY y1-y25; %BETWEEN subject% y1-y25; [y1-y25];