The proposed model can be likened to a moving least squares'' model. It uses a data search procedure in which the intent is to evaluate a number of variables substantively, rather than in terms of formal statistical procedures. (Author)

This paper describes an analytical solution to a common problem in aptitude-treatment interaction (ATI). The researcher is often interested in the comparison between treatments for a large set of attributes. If this set is large, the chance of non-orthogonality is correspondingly large. In these circumstances the analysis and interpretation…

A model for research on teacher effects in which the variance in student outcome post-test performance is attributed to pre-test perfomance; to separate construct domains of student, instructional, and teacher variables; and to interactions between variables in these three construct domains is presented and tested. (Author/JKS)