Generalized symmetric means are redefined in a way which allows them to be calculated for any matrix sampling design. It is proved that these sample generalized symmetric means are unbiased estimates of the analogous population generalized symmetric means. Illustrative examples are given. (Author)

This paper presents an overview of repeated measures designs, designs that measure one group over time, also called within-subjects designs. Both univariate and multivariate designs are discussed, and advantages and disadvantages of each of these designs are considered. The sphericity assumption is examined, and methods are presented to correct…

This paper analyzes three possible research designs using each of the four types of sums of squares in the Statistical Package for the Social Sciences (SPSS). When the design is balanced (i.e., each cell has the same number of observations), all of the SPSS types of sums of squares yield equivalent results (testable hypotheses and sums of squares)…

An experiment is deemed to be valid, inasmuch as valid cause-effect relationships are established, if the results are due only to the manipulated independent variable (possess internal validity) and are generalizable to groups, environments, and contexts outside of the experimental settings (possess external validity). Consequently, all…

The increased interest in reporting effect sizes means that it is necessary to consider what should be included in a primer on effect sizes. A review of papers on effect sizes and commonly repeated statistical analyses suggests that it is important to discuss effect sizes relative to bivariate correlation, t-tests, analysis of variance/covariance,…

The current pace of technological advance has provided an unprecedented opportunity to use innovative simulated tasks in computerized assessment. A primary challenge for the successful use of innovation in assessment rests with the application of sound principles of design to produce a valid assessment. An additional challenge is to maximize the…

Reviews myths which interfere with effectiveness of research, and offers suggestions contributing to a good research study, such as having a good problem, selecting the appropriate research design, qualifying findings as necessary, and being prepared to move on to the next project. Presented at American School Health Association, Philadelphia,…

The difference between statistical significance and substantive significance is discussed. (DB)

Two studies were conducted to compare responses to matrix questionnaires with those to standard questionnaires. In the first study, the matrix format produced significantly fewer returns. A second study comparing matrix and standard questionnaires of equal size found similar response rates but more incomplete returns for the matrix form.…

Bechhofer's procedure for selecting the population with the largest mean from among several populations with known variances is discussed as it applies to the problem of selecting the bivariate normal population with the largest correlation coefficient. Tables of appropriate sample sizes are provided and an example is discussed. (Author/JKS)

A computer program to perform multiple-group factor analysis is presented. Written in Fortran Four, the program has a special feature to handle variables with strong negative correlations. (Author)

The objective of this paper is to review the outputs of selected computer programs often used to carry out a "discriminant analysis" with respect to two purposes of such an analysis, discrimination and classification. The programs selected are three BMD programs. (Author/JKS)

Two approaches to regression-based reading-level-match research designs, one of which used matched Rasch-scaled "w" scores, were tested with 544 primary grade children of different reading levels. Results call into question the conclusion that orthographic skills are compensatory for reading-disabled children. (SLD)