Two studies, both using Type 12 sampling, are presented in which the effects of violating the assumption of essential parallelism in setting confidence intervals are studied. Results indicate that as long as data manifest properties of essential parallelism, the two methods studied maintain precise Type I error control. (SLD)

The distinction between Type 1 and Type 12 sampling in connection with measurement data is discussed, and a method is presented for simulating data arising from Type 12 sampling. A Monte Carlo study is described that shows conditions under which precise confidence level control under Type 12 sampling is maintained. (SLD)

Examines the undercount problem in the 1990 census, the ways in which the Census Bureau has dealt with it in the past, and the Bureau's plans to avoid future undercounts. It also discusses the statistical concept of dual systems estimation in census counting as a means of lessening an undercount. (GR)

Studied three procedures for estimating the standard errors of school passing rates using a generalizability theory model and considered the effects of student sample size. Results show that procedures differ in terms of assumptions about the populations from which students were sampled, and student sample size was found to have a large effect on…

The sample invariant properties of five anchor test equating methods are addressed. Equating results across two sampling conditions--representative sampling and new-form matched sampling--are compared for Tucker and Levine equally reliable linear equating, item response theory true-score equating, and two equipercentile methods. (SLD)

An approximate statistical test of the equality of two intraclass reliability coefficients based on the same sample of people is derived. Such a test is needed when a researcher wishes to compare the reliability of two measurement procedures, and both procedures can be applied to results from the same group. (SLD)

A split-sample replication stopping rule for hierarchical cluster analysis is compared with the internal criterion previously found superior by Milligan and Cooper (1985) in their comparison of 30 different procedures. Situations under which the methods are equivalent or not equally useful are discussed. (SLD)

Explains how the Gibbs sampler can be applied to obtain a sample from the posterior distribution over the parameters of a structural equation model. Presents statistics to use to summarize marginal posterior densities and model checks using posterior predictive p-values. (SLD)

Investigated the item-parameter recovery characteristics of a Gibbs sampling method (J. Albert, 1992) for item-response theory item-parameter estimation and compared them to those from the BILOG computer program. Item-parameter recoveries were similar for both approaches for larger data sets, but overall, BILOG performance was superior. (SLD)

Continues a series on topics in research methodology, statistics, and data analysis techniques for the library and information sciences. Focuses on the basics of sampling for surveys or experimental work, including rationale, terminology, technique, alternative methods, and sample size. (Author/LRW)

The sampling interpretation of confidence intervals and hypothesis tests is discussed in the context of conditional maximum likelihood estimation. Three different interpretations are discussed, and it is shown that confidence intervals constructed from the asymptotic distribution under the third sampling scheme discussed are valid for the first…

Contributes to journalism research by investigating what type and size of probability sample will allow valid inference. Tests the efficiency of probability samples of issues of two monthly consumer magazines over five years, finding a stratified sample more efficient than a simple random sample. (SR)

Discusses sampling bias problems in the use of the greatest lower bound (g.l.b.) to reliability and offers explicit expressions for the second order derivatives. This yields closed form expression for the asymptotic bias of both the g.l.b. and its numerator. Illustrates the approach through a numeric example. (SLD)

Studies concentration aspects of bibliographies, particularly the impact of incompleteness on its concentration values (i.e. its degree of inequality of production of its sources). Models incompleteness by different sampling techniques and discusses implications for the measurement of production inequality in incomplete bibliographies. (Author/LRW)

To determine the extent and nature of alcohol screening and referral services provided by college health centers, the authors conducted a state-stratified, random sampling of 25% of 327 4-year accredited US colleges and universities with health centers. Of the 249 survey respondents, 32% routinely screened students for alcohol use. Urban, public,…