depression levels increased in variability with age in AHBP but not in MLS or AFDP. Bringing these predictors into the model not only makes the specification of the model more realistic (by explicitly incorporating known sources of heterogeneity), but it also provides additional information with which to improve our score estimates for the participants. Indeed, given the incorporation of this extra information, when we generated and plotted factor scores from this model the plots provided an even stronger visual indication of the covariate effects. Figure 3, for instance, depicts study differences in developmental trends, and one can observe both the mean differences across studies and the increasing heterogeneity within AHBP over time.
