The sample size determination is an important issue for planning research. However, limitations in size have seldom been discussed in the literature. Thus, how to allocate participants into different treatment groups to achieve the desired power is a practical issue that still needs to be addressed when one group size is fixed. The authors focused…

The authors examined the robustness of multilevel linear growth curve modeling to misspecification of an autoregressive moving average process. As previous research has shown (J. Ferron, R. Dailey, & Q. Yi, 2002; O. Kwok, S. G. West, & S. B. Green, 2007; S. Sivo, X. Fan, & L. Witta, 2005), estimates of the fixed effects were unbiased, and Type I…

A subset of a real data set was used to illustrate an ad hoc analysis with missing data on multiple response variables. This strategy was initiated with a complete-case analysis to determine some variables that may be deleted with no loss in effects of interest. (SLD)

An evaluation of open education was shown to produce misleading results due to probable regression phenomena. These questionable results are now spread throughout the literature of education, sociology, and psychology. Researchers are advised to review, not merely summarize, prior articles. (Author/PN)

A modified form of the Delphi Technique was used with the School of Education at the University of Northern Colorado to formulate a definition of effective college teaching. (Authors)

Nonparametric and robust statistics (those using trimmed means and Winsorized variances) were compared for their ability to detect treatment effects in the two-sample case. The use of two specialized tests, designed to be sensitive to treatment effects when data distributions are skewed to the right, is not supported by the analyses. (SLD)

The general class of continuous growth models are described and examples representative of growth models suggested for various types of academic and/or physical growth are given. The fan spread hypothesis is discussed in relationship to natural growth models, as well as differential linear growth. (PN)

Effects of response guided experimentation in applied behavior analysis on Type I error rates are explored. Data from T. A. Matyas and K. M. Greenwood (1990) suggest that, when visual inspection is combined with response guided experimentation, Type I error rates can be as high as 25%. (SLD)

The reliability of visual inspection in single-case research was investigated by determining agreement among 5 judges visually inspecting 44 graphs depicting behavior from baseline to intervention. Agreement between visual inspection and statistical procedures was determined. Implications for single-case research are discussed. (SLD)

The purpose of this study was to compare the perceptions of teacher competence within and among three groups of educators as measured by the interview scales of the Instrument for the Observation of Teaching Activities (IOTA). (Auhor)

To deal with nonnormal and heterogeneous data for the one-way fixed effect analysis of variance model, the authors adopted a trimmed means method in conjunction with Hall's invertible transformation into a heteroscedastic test statistic (Alexander-Govern test or Welch test). The results of simulation experiments showed that the proposed technique…

Within-class regression is a method, developed in this paper, of comparing a large number of nonequivalent groups. This study indicated that within-class regression was a less biased method of data analysis and will yield more accurate estimates of treatment effects than analysis of covariance. (PN)

This article describes some insights of the author based on 20 years experience in using the educational research and development process. Problems and strategies related to planning, developing a prototype, and evaluating educational programs and instructional materials are discussed. (Author/JAZ)