I'm currently writing the results part of my thesis and I'm extremely bad at statistics. My variables are
- Dependent variable: Response time (with two levels)
- Factor: manipulation variable (exposing to either one screen or another screen).
- Covariate: 7 point scale.
When checking assumptions I found an interaction between the covariate and the independent/factor, resulting in violating of the homogeneity of the slopes. My teacher said that I have to use the manipulation variable as a categorical variable and the covariate as a “continuous variable” in a multivariate regression analysis in the general linear model (GLM; full factorial). She gave my other fellow students a syntax but forgot me.
Is there somebody who knows have I can get the covariate to be a continuous variable and how to conduct a GLM (so not an ANOVA)?
Thanks in advance!