We conducted three sets of analyses. First, we subjected the lower order scales from each of these instruments to a set of separate principal axis exploratory factor analyses (EFA). We estimated and saved factor scores for factors with eigenvalues >1. We then factored the estimates derived in the first analysis for each instrument separately, using the same analytic methods. We continued this process until we achieved a single factor, which we regarded as an estimate of that instrument’s GFP. We then conducted a cross-instrument principal axis EFA on the GFP estimates derived from each instrument. We expected that the different GFPs embedded in each inventory would cohere into a common higher order factor based on the idea that each inventory ultimately assesses the same GFP.
