Matrix sampling of test items, the division of a set of items into different versions of a test form, is used by several large-scale testing programs. This Digest discusses nine categories of costs associated with matrix sampling. These categories are: (1) development costs; (2) materials costs; (3) administration costs; (4) educational costs; (5)…

This Digest describes matrix sampling of test items as an approach to achieving broad coverage while minimizing testing time per student. Matrix sampling involves developing a complete set of items judged to cover the curriculum, then dividing the items into subsets and administering one subset to each student. Matrix sampling, by limiting the…

This Digest describes four types of errors in mail surveys and summarizes the ways they can be reduced. Any one of these sources of error can make survey results unacceptable. Sampling error is examined through inferential statistics applied to sample survey results. In general, increasing sample size will decrease sampling error when simple…

Among the different types of experimental design are two general categories: true experimental designs and quasi- experimental designs. True experimental designs include more than one purposively created group, common measured outcomes, and random assignment. Quasi-experimental designs are commonly used when random assignment is not practical or…

One of the benefits of performance based assessment is its allowance for the teacher to gather information about how the student understands and applies knowledge. In this Digest, the basic steps a teacher should take to plan and execute effective performance-based assessment are outlined. Coverage includes the steps of planning and executing…

Meta-analysis is a collection of systematic techniques for resolving apparent contradictions in research findings. Meta-analysts translate results from different studies to a common metric and statistically explore the relations between study characteristics and findings. Since G. Glass first used the term "meta-analysis" in 1976, it has…

This digest describes the organization of the National Assessment of Educational Progress (NAEP) and what is included in a typical NAEP assessment. The way in which the NAEP selects students for assessments and how the assessments are used are discussed. The NAEP is a congressionally mandated project of the National Center for Education…

Abuses and misuses of statistics are frequent. This digest attempts to warn against these in three broad classes of pitfalls: sources of bias, errors of methodology, and misinterpretation of results. Sources of bias are conditions or circumstances that affect the external validity of statistical results. In order for a researcher to make…

Samples of the approximately 1,900 requests for information received by the Rural Connection (RC) between September, 1977, and November, 1978, have been selected to give the reader a general idea of the kind of career information requested by guidance counselors in small, rural schools. The requests are organized into two main categories, each…

Advances in computer technology are making it possible for educational researchers to use simpler statistical methods to address a wide range of questions with smaller data sets and fewer, and less restrictive, assumptions. This digest introduces computationally intensive statistics, collectively called resampling techniques. Resampling is a…

Too few researchers understand what statistical significance testing does and does not do, and consequently their results are misinterpreted. This Digest explains the concept of statistical significance testing and discusses the meaning of probabilities, the concept of statistical significance, arguments against significance testing,…

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:…

A discussion of family literacy projects focuses on alternatives to traditional methods of program evaluation. In the first chapter, the distinction between standardized and alternative assessments is clarified and the special evaluation needs of family literacy projects are highlighted. The remainder of the handbook is intended to help program…

Since 1982, studies have shown statistical evidence that career and technical education (CTE) can play a role in reducing the number of high school dropouts, especially among students who are at high risk of dropping out. Case studies at several High Schools That Work sites showed improvements in retention and graduation at the same time that…