I'm running an ancova with one dependent var, one primary predictor, and three covariates (2 dichotomous = d1 & d2, 1 continuous= c1). By default, SPSS holds each covariate at their mean value when producing the estimated marginal means.
1. Could someone explain to me if it is appropriate to hold a dichotomous variable (1, 0) at it's mean when producing the emmeans? If not, what would be the correct command to replace "MEAN" with for the dichotomous variables? The syntax: /EMMEANS=TABLES(XxY) WITH(d1=MEAN d2=MEAN c1=MEAN)
2. For a dichotomous variable (1, 0), does SPSS use the 1 or the 0 as the reference group? Is there a way to change this?
Thanks in advance!