Rotation to a partially specified target matrix in exploratory factor analysis in practice.

The purpose of the present study was to explore the influence of the number of targets specified on the quality of exploratory factor analysis solutions with a complex underlying structure and incomplete substantive measurement theory. We extended previous research in this area by (a) exploring this phenomenon in situations in which both the common factor model and the targeted pattern matrix contained specification errors and (b) comparing the performance of target rotation to an easier-to-use default rotation criterion (i.e., geomin) under conditions commonly observed in practice. A Monte Carlo study manipulated target error, number of targets, model error, overdetermination, communality, and sample size. Outcomes included bias (i.e., accuracy) and variability (i.e., stability) with regard to the rotated pattern matrix. The effects of target error were negligible for both accuracy and stability, whereas small effects were observed for the number of targets for both outcomes. Further, target rotation outperformed geomin rotation with regard to accuracy but generally performed worse than geomin rotation with regard to stability. These findings underscore the potential importance (or caution, in the case of stability) of using extant, even if incomplete and somewhat inaccurate, substantive measurement theory to inform the rotation criterion in a nonmechanical way.

A randomized controlled trial of Hanen's 'More Than Words' in toddlers with early autism symptoms.

BACKGROUND: This randomized controlled trial compared Hanen's 'More than Words' (HMTW), a parent-implemented intervention, to a 'business as usual' control group. METHODS: Sixty-two children (51 boys and 11 girls; M age = 20 months; SD = 2.6) who met criteria for autism spectrum disorders (ASD) and their parents participated in the study. The HMTW intervention was provided over 3.5 months. There were three measurement periods: prior to randomization (Time 1) and at 5 and 9 months post enrollment (Times 2 and 3). Children's communication and parental responsivity were measured at each time point. Children's object interest, a putative moderator, was measured at Time 1. RESULTS: There were no main effects of the HMTW intervention on either parental responsivity or children's communication. However, the effects on residualized gains in parental responsivity from Time 1 to both Times 2 and 3 yielded noteworthy effect sizes (Glass's Δ = .71, .50 respectively). In contrast, there were treatment effects on child communication gains to Time 3 that were moderated by children's Time 1 object interest. Children with lower levels of Time 1 object interest exhibited facilitated growth in communication; children with higher levels of object interest exhibited growth attenuation. CONCLUSIONS: The HMTW intervention showed differential effects on child communication depending on a baseline child factor. HMTW facilitated communication in children with lower levels of Time 1 object interest. Parents of children who evidence higher object interest may require greater support to implement the HMTW strategies, or may require different strategies than those provided by the HMTW curriculum.