I have produced a good-fitting, reliable baseline model according to CFA. The model contains several factors each loaded by several categorical (ordinal) items. I ultimately intend to analyze the factor scores across several grouping variables of interest.
As I understand it, the next step (Before analyzing factor scores) would be to ascertain configural, metric, and scalar invariance of the model across the groups of interest. This is to ensure any inferences made from subsequent analyses (such as ANOVAs) are attributable to true differences between the groups rather than the underlying model differing across the groups.
If the grouping variables take the form of a 2x2 factorial structure, which of the following options is most appropriate?
For example, say you have a 2 (A vs. B) x 2 (X vs. Y) design, do you:
A.) Conduct two sets of invariance tests, one for each of the grouping variables (e.g. one for the A vs. B grouping variable, another for the X vs. Y grouping variable)
B.) Create a new variable representing the 4 possible combinations of the two grouping variables (AX, AY, BX, BY), and conduct the invariance tests based on that
C.) ... Or is there another method for analyzing invariance in a 2x2 between-group scenario?
My intuition is that A will make it difficult or impossible to interpret any interaction I may find. But B may assume the 4 groups vary along a single dimension so I am unsure if I am violating underlying assumptions of the invariance test. Can anyone advise?
Secondarily, assuming invariance holds, any calculated factor scores should be based on this restricted model rather than the unrestricted baseline model, correct?