Imagine that participants completed a series of measures indexing different abilities (memory capacity, learning, etc.) at two timepoints.
The only thing I would like to test at this stage is whether the factor structure at timepoint 1 remains the same at timepoint 2 (time invariance), but I do not necessarily know which factor structure to expect in advance (given that I have multiple separate measures that have thus far not been combined in the literature). Standard invariance testing (reasonably) requires one to specify which items are expected to load on underlying factors which I am currently unable (or very vaguely able) to do.
How should one approach this problem? Is it okay to conduct exploratory factor analysis at timepoint 1 and then follow that with confirmatory factor analysis at timepoint 2 with goodness-of-fit indices at timepoint 2 serving as evidence of time invariance? Or is there something else in the toolbox I could use? Thank you!