Database files and additional log files of Learning Management Systems (LMSs) contain an enormous volume of data which usually remain unexploited. A new methodology is proposed in order to analyse these data both on the level of both the courses and the learners. Specifically, "regression analysis" is proposed as a first step in the…

A challenge associated with traditional mixture regression models (MRMs), which rest on the assumption of normally distributed errors, is determining the number of unobserved groups. Specifically, even slight deviations from normality can lead to the detection of spurious classes. The current work aims to (a) examine how sensitive the commonly…

This article describes a method based on Pratt's measures and demonstrates its use in exploratory factor analyses. The article discusses the interpretational complexities due to factor correlations and how Pratt's measures resolve these interpretational problems. Two real data examples demonstrate the calculation of what we call the…

Smoking, drinking, and illicit drug use are leading causes of morbidity and mortality, both during adolescence as well as later in life. The determination of how well national and local policy and intervention efforts address teen substance use depends largely on the collection of valid and accurate data. Assessments of substance use rely heavily…

This study presents a new approach to estimation of a nonlinear growth curve component with fixed and random effects in multilevel modeling. This approach can be used to estimate change in longitudinal data, such as day-of-the-week fluctuation. The motivation of the new approach is to avoid spurious estimates in a random coefficient regression…

Objective: Life stressors and family socioeconomic position have often been associated with mental health status. The aim of the present study is to contribute to the understanding of the pathways from low socioeconomic position and life stressors to mental problems. Method: In a cross-sectional analysis using data from a longitudinal study of…

A statistical analysis procedure is developed, based on the notion that many educational programs are dynamic interventions in natural growth processes, and is called value-added analysis. The theory of value-added analysis, and several applications are presented. (Author/JKS)

This report demonstrates three applications of case-mix methods using regression analysis. The results are used to assess the relative effectiveness of substance abuse treatment providers. The report also examines the ability of providers to improve client employment outcomes, an outcome domain relatively unexamined in the assessment of provider…

The goals of this article are to (a) describe differences between moderator and mediator effects; (b) provide nontechnical descriptions of how to examine each type of effect, including study design, analysis, and interpretation of results; (c) demonstrate how to analyze each type of effect; and (d) provide suggestions for further reading. The…

The degree to which the chosen units of analysis are likely to produce spurious findings in staged combinations of multiple linear regression procedures are examined. The effects of grouping variables (e.g., classroom, school, and school district) on Procedures such as Coleman's semipartial regression and Mayeske's commonalities, in light of…

Data accumulated over two years were analyzed in order to evaluate two components of a teacher education curriculum--performance objectives and self analysis skills. A multi-step procedure was devised and implemented which uses regression to illustrate the feasibility of implementing the procedure for curricular decision making. This procedure…

This final report summarizes past research and suggests new approaches to the problem of estimating long-term individual constants using path analysis. The general objective of the research was to detect and measure the likelihood that one variable, x, measured at time, t, has a causal influence on another variable, y, measured at a subsequent…

Path analysis, a technique related to multiple regression analysis is used for ascribing causal relationships among variables. Path analysis involves the construction of explicitly formulated causal models and makes the reasoning explicit in the form of path diagrams and structural equations. Regression analysis is then used to construct path…

The accuracy with which regression models estimate treatment effects is dependent upon a number of conditions. The stability of the regression line (a function of sample size and correlation between pretest and posttest) is said to be the most important of these conditions. The utility of regression models is proportional to the size of the…

A relatively simple procedure for modeling periodic components in time series data is presented in this paper, along with an example of the procedure's use with communication data. Similar to multiple regression analysis, the described procedure has four steps that are based on information about periodic waves and their components, how to create…