This paper delineates conditions under which the use of change scores will not produce misleading results, and may perhaps be preferable to other methods of analysis. The validity of change scores in randomized pretest-posttest designs is discussed along with situations where analysis of change scores should be used. (Author/GK)

Two theorems concerning F in analysis of covariance with two groups (experimental and control) and one covariable (pretest score) are presented. The first shows explicitly that F is a direct function of the ratio of the variance about the regression line for the total sample to the variance about the within-group regression line. The second…

The purpose of this study was to determise the relative loss in statistical power of traditional methods of analysis when response-shift bias is present. Five methods of analysis (posttest scores only; postminus pretests; postminus retrospective pretest; postcovaried by pretest; postcovaried by retrospective pretest) were compared. (Author/BW)

Three approaches to initial reading instruction were evaluated to determine their relative effectiveness in establishing word recognition skills. Significant differences between the three groups of children were found in the posttest scores: a special alphabet approach produced highest scores; a phonetic approach, next highest; and a look-say…

Five methods for analyzing data from pretest-post-test research designs are discussed. Analysis of gain scores, with pretests as a covariate, is indicated as a superior method when the assumptions underlying covariance analysis are met. (Author/GDC)

A stratified random sample of 84 student teachers in secondary school academic subject areas was distributed into four treatment groups according to a trichotomization of their scores on the Minnesota Teacher Attitude Inventory (MTAI). Each student teacher taught two 20-minute lessons with the same content to different classes of five pupils. On…

Action research often necessitates the use of intact groups for the comparison of educational treatments or programs. This paper considers several analytical methods that might be used for such situations when pretest scores indicate that these intact groups differ significantly initially. The methods considered include gain score analysis of…

The measurement of change is such a broad topic that this article must limit its focus to a few specific subtopics. These specific topics include: longitudinal research design, attrition in research studies, the statistical analysis of difference scores, and the comparison of analysis of variance (ANOVA) and multivariate analysis of variance…

When two groups, initially dissimilar, undergo different treatments, can subsequent differences be partitioned in such a way that the difference between the two treatments is unbiased? This is the central problem of this paper, and it is confronted by the examination of two levels of information using a Follow Through Evaluation. The first…