Statisticians use words deliberately and specifically, but not necessarily in the way they are used colloquially. For example, in general parlance "statistics" can mean numerical information, usually data. In contrast, one large statistics textbook defines the term "statistic" to denote "a characteristic of a…

Empirical studies estimating the effect of private school competition on student outcomes commonly use the share of Catholics in the local population as an instrument for private school competition. I show that this is not a valid instrument since it is endogenous to private school competition and suggest using instead the local share of Catholics…

Using Microsoft® Excel, several interactive, computerized learning modules are developed to illustrate the Central Limit Theorem's appropriateness for comparing the difference between the means of any two populations. These modules are used in the classroom to enhance the comprehension of this theorem as well as the concepts that provide the…

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)

Populations where free access is denied pose special problems to the survey researcher. In attempting to make general estimates of the size of the composition of the audience in the USSR to Western radio broadcasts, a simulation technique (Mostellerization) has been developed which provides estimates of underlying data from aggregate results. (PD)

Discusses recent labor force trends and how they affect research methodology. Tables are included which indicate new estimates and trends in worklife expectancy, measures of labor force mobility, and trends in mobility rates. (CT)

Relationships between Bayesian ability estimates and the parameters of a normal population distribution are derived in the context of classical test theory. Formulas are presented for practical work with Bayesian ability estimates, and a numerical illustration is provided. (SLD)

These seven articles focus on Shelter and Street Night, a recent Census Bureau effort to include components of the nation's homeless population in the 1990 census count. The success of investigators in Chicago (Illinois), New York City, Los Angeles (California), Phoenix (Arizona), and New Orleans (Louisiana) is analyzed. (SLD)