Hello proc mixed experts,
Variables in my data are person ID, itemduration(time spent answering each question), difficulty(item difficulty). Each person ID answers 150 questions, that is, row 1-row 150 are the same ID, row 151-row 300 are another person ID, etc. Item nested in person(ID), I am trying a multilevel modeling (two level model). Dependent variable is itemduration, level 1 predictor is item difficulty. Model below contains only level1 predictor.
proc mixed data= try method=ml;
class ID;
model itemduration = difficulty / solution outp=t;
random intercept difficulty / subject=ID type=un g solution;
ods output solutionR=randest;
run;
the following is portion of the output data "randest", I can't understand why "std Err Pred" are the same for all IDs. I am trying to get standard errors for each ID. How should I edit the code so that I can get standard errors for each ID?
Thank you for any help.
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