help for mlmprobe

Title

mlmprobe -- Simple slopes for a two-way MLM interaction

Syntax

mlmprobe , pred(string) modx(string)
[options]

pred(string) name of the focal predictor

modx(string) name of the moderator variable

at(numlist) custom moderator values to probe

values(string) meansd (default), quartiles, or tertiles

level(#) confidence level; default 95

Description

mlmprobe computes simple slopes of pred at selected values of modx
using the delta method, based on the coefficient vector and variance-covariance
matrix stored after mixed.

The model must include the interaction as c.pred##c.modx.
Run mixed immediately before mlmprobe.

Stored results

mlmprobe stores the following in r():

r(slope_i) simple slope at moderator value i

r(se_i) standard error at moderator value i

r(t_i) t-statistic at moderator value i

r(p_i) p-value at moderator value i

r(w_i) moderator value for probe i

Example

. mixed math c.ses_c##c.climate_c gender || school:, reml

. mlmprobe, pred(ses_c) modx(climate_c)

. mlmprobe, pred(ses_c) modx(climate_c) values(quartiles)

. mlmprobe, pred(ses_c) modx(climate_c) at(-1 0 1)

Author

Subir Hait, Michigan State University.

Also see

mlmjn, mlmplot, mlmsummary, mlmcenter