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…

About 45 R packages to analyze data using item response theory (IRT) have been developed over the last decade. This article introduces these 45 R packages with their descriptions and features. It also describes possible advanced IRT models using R packages, as well as dichotomous and polytomous IRT models, and R packages that contain applications…

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…

This article introduces a bootstrap generalization to the Modified Parallel Analysis (MPA) method of test dimensionality assessment using factor analysis. This methodology, based on the use of Marginal Maximum Likelihood nonlinear factor analysis, provides for the calculation of a test statistic based on a parametric bootstrap using the MPA…

Recent work has shown that multidimensionally scoring responses from different tests can provide better ability estimates. For educational assessment data, applications of this approach have been limited to binary scores. Of the different variants, the de la Torre and Patz model is considered more general because implementing the scoring procedure…

The "Technology Outlook Australian Tertiary Education 2013-2018: An NMC Horizon Project Regional Analysis" reflects a collaborative research effort between the New Media Consortium (NMC) and Open Universities Australia to help inform Australian educational leaders about significant developments in technologies supporting teaching,…

The purpose of this research is to demonstrate that a systematic approach to the graphical analysis of Rasch model residuals can lead to an increased understanding of ordered response data, and that residual patterns do change in predictable ways, and that summary statistics need not be the only piece of evidence for assuring the fit between model…

Problems involved in providing practical research experience in research methods courses are discussed. The two points in the research process where time is most critical are selecting measures and data collection. This paper suggests using a data base from previous research and having students conduct simulated studies based on randomly selected…

The expert system computer simulation detailed in this report is designed to investigate patterns of valuing in decision-making about dossiers of performance data used in teacher promotion evaluations. The knowledge base for the simulation consists of 111 questions organized into 117 rules. The questions and linked advice were derived from…

Describes the use of online accounting systems as a means of integrating diverse data and providing different levels of analysis for managers. An appendix provides examples of reports produced by online systems. (CLB)

Virtual environments are more and more used in primary schools. One of the most interesting potentialities of these environments is to foster cross-national applications. Yet, this specific feature is not fully exploited. This paper presents a successful virtual learning environment for primary education involving two European countries and…