It is not conceivable that in a mixture or compound a component may exist in a negative ratio. Traditionally, therefore, a negative value could not be plotted on triangular coordinates. However, negative values are explicitly allowed, and the results extend the use of triangular coordinates as shown in this article. (JN)

The difference between the success rates in two treatment groups is related to the treatment-outcome correlation and the overall success rate. A new measure of effect size is proposed, which is easily calculated and interpretable in terms of the ratio of success rates in the treatment groups. (Author/BW)

Randomization tests involve generating all possible assignments of subjects to treatments in order to create a distribution of possible test statistics. The use of a premutation group to enhance the understanding and utility of randomization tests is discussed. (Author/JKS)

This paper decribes the case survey method as a technique to overcome data collection problems and lack of integration of case studies. It outlines the roots of the method, distinguishes it from meta-analysis, describes the process with illustrations from an enrollment decline study, and analyzes its strengths and limitations. (BW)

Presents an exposition of two data reduction methods--single-link and complete-link hierarchical clustering. Emphasis is on statistical techniques for evaluating the adequacy of a completed partition hierarchy and the individual partitions within the sequence. A numerical reanalysis of data illustrates the methodology. (RC)

Reasons for transforming dependent variable measures for use in analysis of variance is discussed, including nonnormality, heteroscedasticity and scale-induced interactions. It is pointed out that nonlinear transformations change the interpretation of interactions, and a method for reducing heteroscedasticity is described. (Author/RM)

The purpose of this research was to analyze recent statistics textbooks in the behavioral sciences in terms of their coverage of exploratory data analysis (EDA) philosophy and techniques. Twenty popular texts were analyzed. EDA philosophy was not addressed in the vast majority of texts. Only three texts had an entire chapter on EDA. None of the…

The importance of research in professional and personal development is increasingly being acknowledged. So why should children not benefit in a similar way? Traditionally, children have been excluded from this learning process because research methodology is considered too difficult for them. Principal obstacles focus around three key barriers:…

This guide gives middle school teachers and principals the tools they need to get answers to their questions about program evaluation. It shows how to use the information to work more effectively and efficiently and explains how to use program evaluation techniques to make sure that the approaches selected really solve the problems of interest.…

This report describes the imputation procedures used to deal with missing data in the National Education Longitudinal Study of 1988 (NELS:88), the only current National Center for Education Statistics (NCES) dataset that contains scores from cognitive tests given the same set of students at multiple time points. As is inevitable, cognitive test…

This book is a step-by-step guide to creating and analyzing linguistic corpora. It defines a corpus as a collection of texts or parts of texts upon which some general linguistic analysis can be conducted. It begins with a discussion of the role that corpus linguistics plays in linguistic theory, demonstrating that corpora have proven to be very…

Potential solutions to applied measurement problems are commonly evaluated using simulated data, largely because it is often impossible, difficult, or prohibitively expensive to supply the needed volumes of real data. However, answers proved by simulation studied generalize real-world problems only to the extent that the simulated data resembles…

Novices often struggle to learn qualitative data analysis, and benefit from intensive assistance. For teaching analysis more efficiently in the classroom setting, the workshop described in this paper explained and demonstrated an inductive, experiential method. The method introduces grounded theory analysis and helps students to identify,…

Over the years, methodologists have been recommending that researchers use magnitude of effect estimates in result interpretation to highlight the distinction between statistical and practical significance (cf. R. Kirk, 1996). A magnitude of effect statistic (i.e., effect size) tells to what degree the dependent variable can be controlled,…

In educational assessment, what students say, do, and sometimes make is observed, and assessors attempt to infer what students know, can do, or have accomplished more generally. Some links in the chain of inference depend on statistical models and probability-based reasoning, and it is with these links that terms such as validity, reliability, and…