When using linear models for cluster-correlated or longitudinal data, a common modeling practice is to begin by fitting a relatively simple model and then to increase the model complexity in steps. New predictors might be added to the model, or a more complex covariance structure might be specified for the observations. When fitting models for…

Conceptual rationales from five research contexts are presented, which all posit unmeasured variables that interact with observed independent variables to produce a complete model of the dependent variable. Strategies for overcoming related difficulties are outlined, including increased longitudinal assessment, oversampling of levels of…

The process of selecting applicants for admission to a new school of medicine (Southern Illinois University School of Medicine) is examined through the use of multivariate regression techniques. More than 250 variables were analyzed and classified as to source of data: student American Medical College Application Service (AMCAS) application,…

The report investigates the validity of career intent and job attitude statements for predicting reenlistments among 54,803 airmen in 101 enlisted specialties. Statements were made while completing Air Force occupational surveys during the period 1966-71. Frequency and percentage distributions characterizing item responses and career decisions of…

This paper poses a research question about how a person's work experience affects his or her earnings and shows how the Cumulative Experience Method (CEM) can provide an answer to the question using all available information in a longitudinal data set. (Author/GDC)

Path analysis was used to provide a comprehensive test of the validity of Tinto's causal model of voluntary withdrawal from a postsecondary institution. This study also tests Tinto's hypothesis of compensatory interactions between social and academic integration and between institutional and goal commitment. (Author/PN)

This paper evaluates empirically the impact of elementary school related factors on the academic achievement of Montreal francophone children. A three-equation model explains simultaneously the level of achievement in mathematics and French and the self-concept of the students in the sample. (Author/LMO)

Education researchers have long been concerned with finding the appropriate method for correlational analysis of hierarchical data. In recent years, the alternative of hierarchical linear modeling (HLM) has come into extensive use. HLM users typically center some or all student-level predictors either at the grand mean or at the school means. This…

One objective of the research was to identify career ladders with the greatest potential for improving retention. This study revealed that a regression model, which takes into account airmen career status and months of service while holding constant aptitude differences, can be used to display cross-sectional attitude data in a longitudinal…

The longitudinal interrelations among age, visual and auditory short-term memory, and the concrete operational tasks of class inclusion and combinatorial reasoning were investigated over four testing occasions in a sample of 134 students, initially ranging from 5 to 12 years in age. The Piagetian task battery involved placement of colored…

Forming a sequence covering the various aspects of the simplex model, four articles are presented here under the following titles: "A Simplex Model for Analyzing Academic Growth", "Analyzing Ratings With Correlated Intrajudge Measurement Errors", "The Correlation of States With Gain", and "The Reliability of…