Risks of life on the street caused by inclement weather, harassment, and assault threaten the unsheltered homeless population. We address some challenges of enumerating the street homeless population by testing a novel capture-recapture (CR) estimation approach that models individuals' intermittent daytime visibility. We tested walking and…

Educational assessment and, more broadly, educational research in the United States have entered into an era characterized by a dramatic increase in the prevalence and importance of test score use in accountability systems. This volume covers a selection of contemporary issues about testing science and practice that impact the nation's public…

The study aimed at finding out whether teachers can identify the courses of reading disabilities in learners. It intended to establish whether teachers have adequate knowledge of identifying learners with reading disabilities, determine the proportion of non-readers in grade five. It also investigated the existing methods and materials teachers…

The Monitoring the Future (MTF) study is an ongoing series of national surveys of American adolescents and adults that has provided the nation with a vital window into the important, but largely hidden, problem behaviors of illegal drug use, alcohol use, tobacco use, anabolic steroid use, and psychotherapeutic drug use. For more than a third of a…

It is argued in this paper that generalizability theory provides a uniquely useful framework for defining and quantifying the dependability of data for decision making. It does so by requiring careful specification of the conditions of measurement and the anticipated sources of variation in the results of the measurement procedure. A distinction…

As strongly suggested by recent work, patterns of gender difference can change because of changes in the selectivity of the sample itself. This is a statistical influence connected with the distributions of female and male scores, rather than a substantive influence related to demographic characteristics of the sample such as age or ethnicity. It…

Sampling error refers to variability that is unique to the sample. If the sample is the entire population, then there is no sampling error. A related point is that sampling error is a function of sample size, as a hypothetical example illustrates. As the sample statistics more and more closely approximate the population parameters, the sampling…

This paper addresses the sample invariant properties of four equating methods (Tucker and Levine linear equating, equipercentile equating through an anchor test, and three-parameter item response theory equating). Data from several national administrations of the Scholastic Aptitude Test served as the source of data for the study. Equating results…

A simple technique, developed by A. Phillips (1987) is used to approximate the covariance between the Mantel-Haenszel log-odds-ratio estimator for a 2 x 2 x k table and the sample marginal proportions. These results are then applied to obtain an approximate variance estimate of an adjusted risk difference based on the Mantel-Haenszel odds-ratio…

Central limit theorem (CLT) is considered an important topic in statistics, because it serves as the basis for subsequent learning in other crucial concepts such as hypothesis testing and power analysis. There is an increasing popularity in using dynamic computer software for illustrating CLT. Graphical displays do not necessarily clear up…

This paper explains the underlying assumptions of the sampling distribution and its role in significance testing. To compute statistical significance, estimates of population parameters must be obtained so that only one sampling distribution is defined. A sampling distribution is the underlying distribution of a statistic. Sampling distributions…

The modeling of longitudinal and multilevel data using a latent variable framework is reviewed. Particular emphasis is placed on growth modeling. Examples are discussed where repeated observations are made on students sampled within classrooms and schools. The concept of a latent variable is a convenient way to represent statistical variation not…

When survey data are statistically analyzed, many times some of the data is missing. If the missing values are not correctly handled, results of the analysis may be dubious and publication may jeopardize the credibility of the organization preparing the report. This study examined four of the more commonly used methods of handling missing data.…

Multivariate methods are being used with increasing frequency in educational research because these methods control "experimentwise" error rate inflation, and because the methods best honor the nature of the reality to which the researcher wishes to generalize. This paper: explains the basic logic of canonical analysis; illustrates that…

A computerized method of preparing a sample of journal issues for testing purposes was created by listing every issue of a set of journals. Random samples of the issues were selected by the computer and printed out. (Author/LS)