Hi, for my 2-wave 2-1-1 mediation, the following syntax is used:
… USEVARIABLES = MT1 MT2 YT1 YT2 XT1; CLUSTER IS TEAM_1; .. !within = MT1 MT2 between = XT1; !DEFINE: CENTER EmpjisT1 EmpjisT2 (GROUPMEAN); Question 2 !DEFINE: CENTER LEjisT1 (GRANDMEAN); ... MODEL: %within% MT1 MT2 YT2; YT2 ON MT1(b); YT2 ON Yt1; MT2 ON Mt1
%BETWEEN% XT1 MT1 YT1; MT2 ON XT1(a);
YT2 ON MT1(b); YT2 ON XT1;
MODEL CONSTRAINT: NEW(indirekt); indirekt=a*b;
OUTPUT: CINTERVAL; ! question 3
I have some questions
1.Specifying the within variables: I would have specified the MT1& MT2 as a within variable (level 1 variable), but get a error message. Is it correct to not specify it as a within only variabe?
2.Centering: I would have centered MT1 and MT2 around the group means, however i get a error message (” GROUPMEAN centering can be applied to WITHIN variables only. Unable to center variable: MT1). Shall i center it around the grand mean then?
3.CI: Demanding CI is not the same as bootrapped CI right? is it enough to interprete the indirect effect CI even though we know a*b is not normally distributed ?
Thanks a lot for providing advice! It is greatly appreciated! Anne
1. You mention MT1 and MT2 on the between-level - that contradicts your notion that they are within only variables. Specifying them as within variables means that they are not involved in between-level modeling.
2. First resolve the issue in 1.
3.CI is not the same as bootstrapped CI. If you are concerned about a*b being non-normal you can use Bayes.