Notes that presence of heterogeneous regression slopes in an analysis of covariance design is equivalent to presence of interaction in randomized-blocks design. Describes modification of the usual graphical representation of heterogeneous regressions that can aid in interpreting significant regions for regression surfaces. (NB)

Teacher perceptions about students' academic abilities are important for several reasons (e.g., instructional decision making, special education entitlement decisions). Not surprisingly, researchers have investigated the accuracy of teachers' decisions. Although some data reveal that teachers are relatively good judges of academic performance,…

The statistical analysis of data from a single-subject design is somewhat controversial. The procedure most often chosen to examine data from a single-subject design involves the visual inspection of the graphed outcome variable over time. Problems associated with this procedure are discussed, and questions about the use of traditional statistical…

Numerous misuses of statistics are described and illustrated, and ways of recognizing and avoiding such misuse are discussed. The following five categories of statistical misuse are identified: a lack of knowledge of the subject matter, the quality of the basic data, the preparation of the study and the report, the statistical methodology, and a…

Evaluates arguments concerning the generality and statistical analysis of single-subject data. Considers the role of philosophy of science in evaluating research methodology. Single-subject data have special relevance for psychologists and educators who focus on the individual but statistical techniques for analyzing data have numerous…

In many practical settings, essentially the same differential item functioning (DIF) procedures have been in use since the late 1980s. Since then, examinee populations have become more heterogeneous, and tests have included more polytomously scored items. This paper summarizes and classifies new DIF methods and procedures that have appeared since…

Offers suggestions for proper procedures for authors to use--and some pitfalls to avoid--when writing studies using factor analysis methods. Discusses distinctions among different methods of analysis, the adequacy of factor structure, and other notes of caution. Encourages authors to ensure that their research is statistically sound. (RJM)

Multiple regression and correlation (MRC) methods form a flexible family of statistical techniques that can address a wide variety of different types of research questions of interest to rehabilitation professionals. In this article, we review basic concepts and terms, with an emphasis on interpretation of findings relevant to research questions…

It is curious that so many people are accepting of statistics despite Disraeli's famous aphorism concerning "three kinds of lies." This acceptance certainly seems to hold for education statistics, especially when they imply something negative about American public schools. Sometimes people accept statistics because they are not in a position to…

Despite the role that institutional service plays in the tenure and promotion process, quantitative research in this area has focused on the percentage of time spent on service and administration, with little research on specific aspects of faculty service. Committee work, one of the most important parts of faculty service, has been particularly…

Despite the best of intentions, qualitative researchers can be faced, in some circumstances, with having to make meaning from thin, or less than optimal, data. Using a real study as context, the authors describe the ways that they made sense of their thin data on teachers' perceptions of a large-scale evaluation instrument. They propose a…

This paper analyses technology-based instruction on data-analysis with box plots. Examples of instruction taken from the research literature inform a study of two classes of 17 year-old students (upper secondary) in which the mathematical relationships that their teachers targeted are distinguished as being, or not being, relevant to statistical…

Dedicated to describing all U.S. states' and territories' arts agencies at the close of 1974, this research report complies and analyzes information about their: (1) structure, management, organization, and relationships with other groups and organizations; (2) functions and practices; and (3) receipts and expenditures. State governing councils…

Discusses three topics related to interpretation of discriminant analyses (DA's): (1) partial F ratios and partial Wilks's lambdas for predictor variables in standard, step-down, and stepwise DA's; (2) relation of goals of classification to definition/evaluation of classification rules; and (3) significance tests for total hit rates in internal…

Comments on some methodological limitations of the research base of "The Bell Curve": blind use of the normal distribution (bell curve); avoidance of nonnormal statistical distributions, which are more appropriate for some social and economic characteristics; copious use of percentiles and quintiles, inappropriate with nonnormal…