This study estimated a component of within-school variance which has been overlooked in policy research studies and program evaluations performed to date: the effect on pupil performance of different teachers within a single school or program. Results indicated that teacher effects accounted for 30 to 40 percent of within-school variance. (Author/…

The evaluation design, which prescribes when and from whom to gather data, is described as significant because it can lend credibility to evaluation results. The objectives of this booklet are to aid the evaluator in: choosing a design; putting it into operation; and analyzing and reporting the data. Examples include both formative and summative…

A review of the literature suggests that choice of control group may have affected the policy implications of the major evaluations of governmental training programs. It is argued that the usual evaluation designs underadjust for preprogram differences between trainees and the control group and thus yield biased estimates of program impact.…

The utility of the biomedical model of adjusted statistics is demonstrated. The model is recommended for use by educational researchers to randomize subjects for a more accurate estimate of school programs' success or failure when compared across classrooms or other units. (Author/MH)