are you trying to compare slopes?
Hi @Byron_JMP, thank you for your reply.
I need to test the homoscedasticity of some variables and then perform the analysis of (M)ANCOVA. As I understand, some stats methods for oneway are not applied to a repetead-measures design. For example, it seems that the test of homoscedascity for a oneway is not equal to a repetead-measures design. So, I suppose it follows a different procedure for repeated-measure (M)ANCOVA.