This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

Education research rarely lends itself to large scale experimental research and true randomization, leaving the researcher to quasi-experimental designs. The problem with quasi-experimental research is that underlying factors may impact group selection and lead to potentially biased results. One way to minimize the impact of non-randomization is…

This paper introduces an empirical strategy to estimate dynamic treatment effects in randomized trials that provide treatment in multiple stages and in which various noncompliance problems arise such as attrition and selective transitions between treatment and control groups. Our approach is applied to the highly influential four year randomized…

Discussed problems and deficiencies in past research on clinical diagnosis, pertaining to sampling problems with regard to clinical subjects studied, adequacy of control groups, base rates, clinical versus statistical significance, lack of cross-validation, and problems due to reliance on inadequate schemes of classification. Future research is…

In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups…

Problems associated with the analysis of data collected using the Solomon Four Group Design are discussed. The design includes an experimental group and a control group that have been pretested and posttested, and an experimental and a control group that have been posttested only. A sample problem is approached in three different ways. First, the…

This book is designated for an audience of the practitioners of education, especially those located in elementary schools. It is designed to investigate and explain research methods, terms, and concepts so that the reader can narrow down the many ways things are known or said to be known. Included in this book are chapters on the research process…

The Walsh and Carballo evaluation of the effectiveness of transitional bilingual education programs in five Massachusetts communities, has the following flaws: (1) the sample of school districts studied suffered from "self-selection bias"; (2) the sample does not include a single large, urban school district; (3) the student samples…

The failure of educational research to fully allow for limitations in methodology when drawing conclusions is faulted. In addition to this, a failure on the part of the media--educational and other--to fully publicize these limitations is also criticized. Methodological shortcomings of the 1977-78 American Institutes of Research (AIR) study of…

In evaluation research studies, it often occurs that several program participants (experimentals) drop out of the program prior to completion. Since noncompleters generally differ substantially from completers in many respects, a control group which originally was representative of the participant group will most likely not be representative of…

The purpose of this study was to measure the effectiveness of a monolingual versus a bilingual approach to the education of second-grade, Spanish-speaking children in New York City. The results were determined by measuring achievement in reading, which showed that the bilingual approach was indeed the more effective. The report includes an…

Four types of control groups are commonly used in cognitive manipulation studies: (1) no-treatment; (2) practice with own methods; (3) practice and training with competing treatments; and (4) practice and training with irrelevant treatments. There are problems associated with the use of each group as a baseline for identifying the "true"…

Follow Through is a longitudinal program instituted by the U.S. Office of Education in which a variety of curriculum models have been implemented in a number of locations nationwide. Because services are provided from kindergarten through third grade, many children enter and leave the program at points not coterminous with the treatment itself.…

The focus of future Follow Through research should be oriented toward showing what can be done in order to offer information to both federal and local planners on which systems of curriculum design, classroom management, and parent involvement appear to be most effective. To assure this goal, the issues of program efficacy and implementation…

In order to make policy decisions, educators must evaluate educational research proposals and projects. Findings immediately related to practice are often inadequate, omitting the theoretical establishment of principles by which we can explain and predict the phenomena of our world. These theoretical linkages to the practical world of…