Experimental psychology is witnessing an increase in research on individual differences, which requires the development of new tasks that can reliably assess variations among participants. To do this, cognitive researchers need statistical methods that many researchers have not learned during their training. The lack of expertise can pose…

The purposes of this study were to test the structural validity and to test the parameters invariance of the self-discipline measurement model for good student citizenship among the models, using the data from the 1,047 complete questionnaires and the reducing length questionnaires with multiple matrix sampling technique. The sample size of this…

Authors conclude that, in the world of real data sample correlation matrices, Guttman's stronger lower bound is not of practical use in determining the effective number of common factors. (Authors/CB)

First purpose of this study was to investigate empirically the accuracy of prediction using regression weights selected through the use of variance-reduction procedures. (Author)

The equivalency of item sampling and student sampling of attitudes of college students was investigated. A factor analysis of student-sampled data collected during Spring 1968, was compared with a factor analysis of item-sampled data collected each quarter from Fall 1968, through Winter 1970, at Mankato State College, using the Campus Environment…