A study was made to ascertain how large a sample is needed to make media effectiveness decisions which are generalizable to the total educable mentally handicapped (EMH) population. The method employed in the study involved pretesting and posttesting a sample of 70 primary and intermediate EMH children on the content of a filmstrip. Statistical…

Much of the literature on random-digit-dial (RDD) response rates focuses on the benefits and drawbacks of various screening and sampling procedures. The common assumption is that enumeration is more invasive, leading to lower response rates, but there are concerns about population coverage and self-selection with other methods. When the target…

Differences between means, variance, and correlation parameter estimates from a full school sample and samples restricted by parental consent were studied with 1,609 students at continuation high schools and 1,192 at traditional high schools. Sample bias due to consent policies may not be a substantive problem, especially if a telephone consent…

Tracking and two statistical methods (probability weighting and sample selection modeling) were studied as ways to minimize bias attributable to sample attrition in school-based studies. Data on student smoking from 30 middle schools illustrate that sample weighting yields the best results, with estimates superior to sample selection and much less…

Simple methods for detecting attrition (nonresponse) in longitudinal evaluations are reviewed, focusing on regression-based analyses of data from a longitudinal evaluation. The approaches are illustrated with data from the Fort Bragg Evaluation, an evaluation of a major demonstration in children's mental health services. (SLD)

Demonstrates a statistically valid method allowing students to explore randomization. Described are two examples: counting techniques for a small set of data and simulation for a large sample. (YP)

The effects of the violation of the assumption of normality coupled with the condition of multicollinearity upon the outcome of testing the hypothesis Beta equals zero in the two-predictor regression equation is investigated. A monte carlo approach was utilized in which three differenct distributions were sampled for two sample sizes over…

This paper examines issues related to the statistical power of impact estimates for experimental evaluations of education programs. The focus is on "group-based" experimental designs, because many studies of education programs involve random assignment at the group level (for example, at the school or classroom level) rather than at the student…

The Schools and Staffing Survey (SASS) is the largest sample survey of the characteristics and conditions of U.S. public and private schools and their teachers and principals. This booklet provides an overview of the aims of the SASS and the information it provides. In 1999, nearly 124,000 SASS questionnaires were mailed to collect information on…

The 1996 National Household Education Survey (NHES:96) was a random digit dial telephone survey of households that was developed by the National Center for Education Statistics and conducted by Westat, Inc. The NHES:96 included two topical survey components, "Parent and Family Involvement in Education," (PFI) which collected data about…

This volume documents the data collection of the 1990-91 Schools and Staffing Survey (SASS). People wishing to determine whether their research needs can be served by SASS data will find a description of the survey's contents and objectives in the Overview. This volume contains the following chapters: (1) "Overview"; (2) "Changes in…

An evaluation of the rules-of-thumb used to determine the minimum number of subjects required to conduct multiple regression analyses suggests that researchers who use a rule of thumb rather than power analyses trade simplicity of use for accuracy and specificity of response. Insufficient power is likely to result. (SLD)

This paper summarizes and highlights some of the critical developments, issues, and trends which impact the work of survey research. The issue of preventing or minimizing nonresponse bias by successfully obtaining cooperation from people being surveyed continues to be of concern to survey research professionals. The most effective response rate…

The sampling errors of maximum likelihood estimates of item-response theory parameters are studied in the case where both people and item parameters are estimated simultaneously. A check on the validity of the standard error formulas is carried out. The effect of varying sample size, test length, and the shape of the ability distribution is…

Practical information is provided, in a question and answer format, for community college officials who are planning to conduct a community needs assessment. A brief discussion of the usefulness of needs assessment surveys to the college planning process is followed by descriptions of eight steps to be followed in planning and conducting a survey:…