This paper investigated consequences of measurement error in the pretest on the estimate of the treatment effect in a pretest-posttest design with the analysis of covariance (ANCOVA) model, focusing on both the direction and magnitude of its bias. Some prior studies have examined the magnitude of the bias due to measurement error and suggested…

We revisit the merits of the retrospective pretest-posttest (RPP) design for repeated-measures research. The underutilized RPP method asks respondents to rate survey items twice during the same posttest measurement occasion from two specific frames of reference: "now" and "then." Individuals first report their current attitudes…

The authors empirically examined whether the validity of a residualized dependent variable after covariance adjustment is comparable to that of the original variable of interest. When variance of a dependent variable is removed as a result of one or more covariates, the residual variance may not reflect the same meaning. Using the pretest-posttest…

This article presents a method to evaluate pretest effects on posttest scores in the absence of an un-pretested control group using published results of pretesting effects due to Willson and Putnam. Confidence intervals around the expected theoretical gain due to pretesting are computed, and observed gains or differential gains are compared with…

Pretest-posttest experimental designs are often used in randomized control trials (RCTs) in the education field to improve the precision of the estimated treatment effects. For logistic reasons, however, pretest data are often collected after random assignment, so that including them in the analysis could bias the posttest impact estimates. Thus,…

Problems in measuring change abound. For many purposes, a pretest score is best treated as any other measure obtained at the time of the pretest. Where appropriate, regression analyses that treat the pretest no differently from other independent variables, and the posttest as the dependent variable avoid many difficulties introduced by gain…

A sizable representative subsample of the standardization group for the Metropolitan Achievement Tests participated in both the Fall and Spring standardization programs. Fall and Spring test records were matched for all such pupils and Fall-Spring "growth expectancies" were derived. Additionally, the sample was split into three subgroups…

A computer simulation procedure was developed to reproduce the overall pattern of results obtained in the Educational Testing Service Growth Study. Then simulated data for seven sets of 10,000 to 15,000 cases were analyzed, and findings compared on the basis of correlations between estimated and true growth scores. Findings showed that growth was…

This study was undertaken to determine whether students who had received less adequate instruction and were less able in scholastic aptitude test performance than the subjects in previous studies might benefit more from special instruction. Specially prepared linear programed materials were developed in the verbal and the mathematical areas.…

This program, funded by the State of Michigan, was designed to provide compensatory education in basic reading and arithmetic skills for elementary school children with serious deficiencies in these areas. The composite achievement scores of the 1970-71 Michigan Educational Assessment Program were used to establish eligible school districts.…

Twelve common errors which can invalidate an otherwise sound evaluation are identified, and ways to avoid them are presented. The hazards are: (1) grade-equivalent scores; (2) inappropriate statistical adjustments with nonequivalent control groups; (3) administering norm-referenced tests at inappropriate times of the school year; (4) inappropriate…

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…

Two methods of reading instruction (homogeneous grouping and graded classes) are compared for 165 students in 8 rural North Dakota schools by raw gain scores, residual gain scores, and the analysis of covariance. (CK)