Experiments where participants are randomly assigned into experimental and control groups are often regarded as the ideal approach to evaluation of labor force policies. This paper shows that such design can yield misleading and incomplete information. It proposes alternate designs that permit estimation of marginal as well as average program…

This booklet contains questions and answers about random assignment in program evaluation and intervention research. The main purpose of program evaluation research in education is to determine whether programs help the students they are designed to serve and whether new ideas for education programs still under development are worthy of extension…

Control subjects completed Book IV of the Edwards Personality Inventory under instructions to be honest while experimental subjects were instructed to fake so as to make an excellent impression while also concealing their faking. Differences between group means were small. (Author/EK)

The effects of in-service training programs on their participants are evaluated. (CK)

The advantages and assumptions of analysis of covariance (ANCOVA) and an alternative approach to ANCOVA which uses simultaneous and nonsimultaneous inference techniques are presented with an example of the latter's use. This approach is advocated for situations where it is suspected that dependent measures are a function of some initial aptitude…

Rationale and procedures for conducting process analysis in evaluation research are discussed. Two different procedures for estimating mediation are discussed, as well as procedures for examining whether a treatment exerts its effects, in part, by altering mediating process that produces outcome. Benefits of process analysis in evaluation research…

This study examined the effects of performance patterns and attributional information regarding performance causes on attributions and task persistence in fourth and fifth graders who tended to minimize effort as a cause of school performance. Performance patterns did not influence attributions or persistence. Effort feedback influenced…

The sciences of nutrition and toxicology require deep methodological reexamination. (JD)

Problems associated with randomization tests in single- case experiments are discussed. This article follows a discussion of randomization tests in single case studies in the same issue of this journal. (See TM 505 799; 505 801).(Author/JKS)

The purpose of this paper is to demonstrate how many more subjects are required to achieve equal power when testing certain hypotheses concerning proportions if the randomized response technique is employed for estimating a population proportion instead of the conventional technique. (Author)

McNemar's discussion of error reduction in a mixed two-group design fails to provide an algebraic presentation of this error reduction. This paper presents not only the algebraic development of the error term but shows that under certain conditions mixing may increase experimental error. (Author)

The selection of subjects for research on learning disabilities is a function of contemporary notions about learning disabilities, the purpose of the study and level of knowledge about the topic, and practical constraints. Denigrations of the extant research database, along with unaffordable demands for subject selection and descriptions, threaten…

Can infants below age 1 year learn words in one context and understand them in another? To investigate this question, two groups of parents trained infants from age 9 months on 8 categories of common objects. A control group received no training. At 12 months, infants in the experimental groups, but not in the control group, showed comprehension…

This study investigated the possibility of enhancing the level of preschoolers number sense by introducing two intervention programmes, "Lets think!" and "Young children with special educational needs count, too!" Forty-five preschoolers, mean age 66.4 months, were randomly assigned to the experimental and control groups. The…

Basic motor skills development is achieved through the implementation of different types of physical education programs. The purpose of this study was to investigate and to compare the effect of a developmentally appropriate music and movement program and of a developmentally appropriate physical education program on the development of jumping and…