Underlying all What Works Clearinghouse (WWC) products are WWC Study Review Guides, which are intended for use by WWC certified reviewers to assess studies against the WWC evidence standards. As part of an ongoing effort to increase transparency, promote collaboration, and encourage widespread use of the WWC standards, the Institute of Education…

This guide will help researchers design and implement impact studies in education so that the findings are more generalizable to the study's target population. Guidance is provided on key steps that researchers can take, including defining the target population, selecting a sample of schools--and replacement schools, when needed--managing school…

Descriptive analyses of socially important or theoretically interesting phenomena and trends are a vital component of research in the behavioral, social, economic, and health sciences. Such analyses yield reliable results when using representative individual participant data (IPD) from studies with complex survey designs, including educational…

This document provides step-by-step instructions on how to complete the Study Review Guide (SRG, Version S3, V2) for single-case designs (SCDs). Reviewers will complete an SRG for every What Works Clearinghouse (WWC) review. A completed SRG should be a reviewer's independent assessment of the study, relative to the criteria specified in the review…

This paper provides practical guidance for researchers who are designing and analyzing studies that randomize schools--which comprise three levels of clustering (students in classrooms in schools)--to measure intervention effects on student academic outcomes when information on the middle level (classrooms) is missing. This situation arises…

The Programme for International Assessment of Adult Competencies (PIAAC) will establish technical standards and guidelines to ensure that the survey design and implementation processes of PIAAC yield high-quality and internationally comparable data. This document provides a revised version of the technical standards and guidelines originally…

Presents the objective and methodology chosen for the construction of a global emissions source database called EDGAR and the structural design of the database system. The database estimates on a regional and grid basis, 1990 annual emissions of greenhouse gases, and of ozone depleting compounds from all known sources. (LZ)

Examines the potential for the replacement of CFCs for historic uses with substituting technologies. The potential production and emissions of the principal HCFCs and HFCs are calculated for the next 25 years. (LZ)

The popularity of sample surveys in evaluation and research makes it necessary for consumers to tell a good survey from a poor one. Several sources were identified that gave advice on how to evaluate a sample design used in a survey study. The sources are either too limited or too extensive to be useful practically. The purpose of this paper is to…

This article presents a fairly quick, easy way to decide what size sample is needed for a survey, given a desired level of confidence and degree of accuracy. The method proposed will work on any multiple response instrument. A technical mathematical explanation is also included. (GK)

Expresses the importance of scientifically based research in education reform and explains how to judge the validity of educational research. Describes control groups, randomized and matched experiments, statistical educational significance, sample size, and the difference between scientifically based and rigorously evaluated research. (Contains…

A concise table is presented based on a general measure of magnitude of effect which allows direct determinations of statistical power over a practical range of values and alpha levels. The table also facilitates the setting of the research sample size needed to provide a given degree of power. (Author/CM)

This paper helps researchers develop criteria for conducting surveys. Cost considerations frame the paper's suggestions. Specifically, the text advises that researchers consider the human and material resources needed, type of survey instrument, medium for conducting the survey (mail, telephone, personal interview, etc.), data analysis…

The main features of a multiple site, structured case study design are presented. The nature of explanatory patterns, how case study investigators pursue and recognize valid patterns, and how an analyst can apply the same logic to cross-site analysis are discussed. (Author/BW)

A guide to survey research is presented for both novice and experienced researchers. Steps of the survey research process are covered: (1) planning the survey to determine the purpose of the study, collecting background information, designing the sample, and making a time line for completing the project; (2) questionnaire design, including the…