The sensitivity of marginal maximum likelihood estimation of item and ability (theta) parameters was examined when prior ability distributions were not matched to underlying ability distributions. Thirty sets of 45-item test data were generated. Conditions affecting the accuracy of estimation are discussed. (SLD)

Inference is considered for the marginal distribution of "X" when ("X", "Y") has a truncated bivariate normal distribution. The "Y" variable is truncated, but only the "X" values are observed. A sample of 87 Otis test scores is shown to be well described by this model. (SLD)

Kids Count, a project of the Annie E. Casey Foundation, is a national and state by- state effort to track the status of children in the United States. By providing policymakers and citizens with benchmarks of child well-being, Kids Count seeks to enrich local, state, and national discussions concerning ways to secure better futures for all…

This study assessed farmers' willingness to pay (WTP) for extension services. The Contingent Valuation Method (CVM) was used to assess the amount which farmers are willing to pay. Primary data on the demographic, socio-economic variables of farmers and their WTP were collected from 228 farmers selected randomly in a stage-wise sampling procedure…

The research project presented in this article was set in the Swedish school context and carried out on a set of compulsory national tests for English, Swedish, and mathematics used at the end of compulsory school. The aims were: (a) to gain a deeper knowledge of the internal structure of the tests and (b) to separate individual performance from…

In this article, the author documents the learning disadvantage of rural primary school students in sub-Saharan Africa and attempts to identify the factors underlying such disadvantages. Analyzing data from 14 school systems participating in the second study of the Southern and Western Africa Consortium for Monitoring Educational Quality (SACMEQ…

M. J. Kolen, B. A. Hanson, and R. L. Brennan (1992) presented a procedure for assessing the conditional standard error of measurement (CSEM) of scale scores using a strong true-score model. They also investigated the ways of using nonlinear transformation from number-correct raw score to scale score to equalize the conditional standard error along…

A study examined whether, holding work experience and sex constant, exposure to vocational education during secondary school was related to incidence of nonfatal work-related injuries. Data were from the 1987 and 1988 annual National Longitudinal Surveys of Labor Market Experience interviews of young adults who were between 14 and 21 years old on…

Many testing programs include a section of optional questions in addition to mandatory parts of a test. These optional parts of a test are not often truly parallel to one another, and groups of examinees selecting each optional test section are not equivalent to one another. This paper provides a general method based on missing-data methods for…

In educational research, nonessential factors are commonly ignored and when accounted for, they are often treated statistically as fixed effects. Yet many researchers in these situations generalize their findings beyond the specific levels selected; however, the analyses may require treating the factor as a random effect. Such inappropriate…

By employing a concomitant variable, researchers can reduce the error, increase the precision, and maximize the power of an experimental design. Blocking and analysis of covariance (ANCOVA) are most often used to harness the power of a concomitant variable. Whether to block or covary and how many blocks to be used if a block design is chosen…

The purpose of this investigation was to examine historical changes in aptitude scores. Recent literature suggesting a decline in the quality of the U.S. workforce is reviewed, and an expectation that score distributions on aptitude tests have shifted in a negative direction is presented. Archival analyses of normative data for the Short…

The purpose of this study was to develop a single procedure for comparing population variances which could be used for distribution forms. Bootstrap methodology was used to estimate the variability of the sample variance statistic when the population distribution was normal, platykurtic and leptokurtic. The data for the study were generated and…

The 1984-85 age-grade distribution for the New York City Public Schools shows that one-third of the city's approximately 850,000 general education and resource room students were above the standard age for their grade. The proportion of overage students increased in the upper grades; in grades nine, ten, and eleven, over half were above standard…

This population profile summarizes a range of demographic, social, and economic data collected by the Census Bureau during 1983 and 1984. Geographic coverage is primarily for the nation as a whole, although some demographic data at the State level are also included. The areas covered are as follows: (1) national population trends; (2) national…