I am conducting longitudinal multilevel models with Daily observations as level-1 variable and PARTICIPANT as level-2 variable. Predictors and outcome variables are measured every day.
I am confused about the use of TIME in SPSS syntax. Models that I find use TIME both as a predictor and as the level-1 identifier. Is this appropriate?
Some models include the following row and some dont:
/REPEATED=time | SUBJECT(Participant) COVTYPE (ar1)
Some of them only add TIME as a predictor without the row above.
What is the correct way to write SPSS syntax if I want to indicate that TIME is the level-1 measurement unit? Is the command above indispensable? Do I need to /can I also add TIME as a predictor (fixed or random effect).