Enzymes are nature's catalysts, mediating chemical processes in living systems. The study of enzyme function and mechanism includes defining the maximum catalytic rate and affinity for substrate/s (among other factors), referred to as enzyme kinetics. Enzyme kinetics is a staple of biochemistry curricula and other disciplines, from molecular and…

Developmental scientists are often interested in subgroups of people who share commonalities in aspects of development; these subgroups often cannot be captured directly but instead must be inferred from other information. Mixture models can be used in these situations. Two specific types of mixture models, latent profile transition analyses and…

The present guide provides a practical guide to conducting latent profile analysis (LPA) in the Mplus software system. This guide is intended for researchers familiar with some latent variable modeling but not LPA specifically. A general procedure for conducting LPA is provided in six steps: (a) data inspection, (b) iterative evaluation of models,…

The "Integrated Approaches to Supporting Child Development and Improving Family Economic Security" project was conducted by Mathematica Policy Research and Northwestern University for the Office of Planning, Research and Evaluation (OPRE), in the Administration for Children and Families (ACF) at the U.S. Department of Health and Human…

Suppose an education researcher wants to test the impact of a high school drop-out prevention intervention in which at-risk students attend classes to receive intensive summer school instruction. The district will allow the researcher to randomly assign students to the treatment classes or to the control group. Half of the students (the treatment…

We extend a unified and easy-to-use approach to measurement error and missing data. In our companion article, Blackwell, Honaker, and King give an intuitive overview of the new technique, along with practical suggestions and empirical applications. Here, we offer more precise technical details, more sophisticated measurement error model…

Inclusive education (IE) and the special education services related to it are relatively new in Oman. Efforts to manage special/inclusive education face many challenges due to a number of culturally rooted factors. Further, empirical research on IE in Oman is scarce and there is a need to advance IE discourse based on empirically validated…

The growing prominence of value-added models for measuring teacher effectiveness has prompted a recent surge in policies that consider students' classroom performance part of a teacher's evaluation. Yet, in light of the criticism and limitations of the current models, whether and how evaluation systems will adapt over time is unclear. This paper…

The purpose of this paper is to offer an analytic perspective to policy makers and educational practitioners regarding how to use longitudinal achievement data to evaluate schools. The authors further discuss the potential practical applications of their models for superintendents, researchers, and policy makers. The premise of the study is that…

In discussing the place of diverse qualitative research within psychological science, the authors highlight the potential permeability of the quantitative-qualitative boundary and identify different ways of increasing communication between researchers specializing in different methods. Explicating diversity within qualitative research is…

To provide a model for analyzing the educational experiences of high school students, this article presents a profile of academic, vocational, and miscellaneous courses offered, and their enrollment, in four Nebraska school districts. Statistics are presented for subject areas within the above categories. Suggestions for applying the model are…

Research with older persons suffering from physical illness presents numerous challenges to gerontologists. Issues of conceptualization pertaining to the definition of illness, its location in the research paradigm, and the context in which illness occurs must be addressed prior to dealing with methodological problems. Access to physically ill…

This article describes soft modeling with partial least squares in a nontechnical manner and suggests its greater use in special education research. This approach allows model building and evaluation in situations with high complexity but without well-articulated theories. (DB)

Analyzes the application of levels of deficits or supports in the classification of mental retardation in published research. Analysis of data from three professional journals indicated that the supports model of classification has had no significant impact in subject descriptions reported in mental-retardation research. Implications for teacher…

The REDSIL model for ongoing evaluation of gifted education programs involves interviewing stakeholders, isolating and categorizing critical study issues, designing a data collection plan that uses several forms of qualitative methods, implementing the plan, analyzing data, searching literature relative to each issue, analyzing data again, and…