What is the substantive interpretation of an interaction in the absence of a main effect? Statistically I understand that the interaction modifies the main effect, but how to interpret this from a substantive perspective?
Example output (cropped from
nlme model in R):
Value Std.Error DF t-value p-value socialinteraction_cwp 0.1702094 0.03855630 26843 4.414567 0.5037 relstat_Single 0.2796805 0.23039908 485 1.213896 0.2254 socialinteraction_cwp:relstat_Single -0.0455506 0.02069088 26843 -2.201483 0.0277
socialinteraction_cwp is within-person centered amount of social interaction and
relstat_Single is a dummy code for relationship status single (1) compared to married (0).