The author uses mathematical models that involve only algebra and a few basic ideas in discrete probability to describe the frequency of conception in large human societies. A number of calculations which can be done by students as exercises are given. (MN)

Vector sum of a white noise in an unknown hyperspace and an Ornstein-Uhlenbeck process in an unknown line is observed through sharp linear test functions over a finite time span. Parameters associated with white noise are determinable and index measure-equivalence classes in relevant sample space. Intraclass relative density provides a basis for…

This paper provides cost-effectiveness measures that can be used for analyzing secondary vocational programs in terms of program effectiveness against cost-efficiency. (Author/IRT)

Describes a mathematical salary-growth model which serves as the basis of an objective conversion procedure (providing a more equitable merit-pay plan). Also demonstrates how this procedure was used and discusses additional benefits (particularly pertinent to institutions using arbitrary criteria to determine pay increments and have lock-step…

Estimation theory in educational statistics and the application of hierarchical linear models are reviewed. Observations within each group vary as a function of microparameters. Microparameters vary across the population of groups as a function of macroparameters. Bayes and empirical Bayes viewpoints review examples with two levels of hierarchy.…

In the process of fitting a quantitative synthesis model, the assumption of homogeneous effect size variation is assessed via omnibus test statistics. Graphical representations of data on techniques for teaching composition skills are used to help determine the extent to which sample estimates deviate from modeled population estimates. (TJH)

Presents a model for the geometric analysis of the relationship between information queries and information systems retrieval, and demonstrates the utility of this analysis by its application to six conventional information retrieval similarity measures and a seventh spreading activation measure. (Author/CLB)

The development of a nonparametric K-sample test for equality of slopes using Puri's generalized L statistic is presented. The test is recommended when the assumptions underlying the parametric model are violated. This procedure replaces original data with either ranks (for data with heavy tails) or normal scores (for data with light tails).…

Mathematical observations are made about some continuous curves, called transitions, encountered in well-known experiences. The transition parabola, the transition spiral, and the sidestep maneuver are presented. (MNS)

The purpose of the present paper is to derive linear equating methods for the common item nonequivalent populations design from explicitly stated congeneric type test score models. The equating methods developed are compared with previously developed methods and applied to five professionally constructed examinations administered to approximately…

The purpose of this paper is to propose a general multicomponent latent trait model (LTM) for response processes. It combines the linear logistic LTM with the multicomponent LTM. Joint maximum likelihood estimators are presented for parameters of the general multicomponent LTM and an application to cognitive test items is described. (Author/BW)

It is shown that for equal parameters explicit formulas exist, facilitating the application of the Newton-Raphson procedure to estimate the parameters in the Rasch model and related models according to the conditional maximum likelihood principle. (Author/LMO)

Using data from the National Longitudinal Survey of Young Men, this paper reveals that earnings below expectations induce a return to school. Appended are 12 references. (MLF)

Statistical methods are presented to facilitate a more complete analysis of results obtained when a scaling model is applied to data from two or more groups. Various kinds of scaling models are considered here in the multiple-group context. (Author/LMO)

Section pre-equating (SPE) equates a new test to an old test prior to the actual use of a new test by making extensive use of experimental sections of a testing instrument. SPE theory is extended to allow for practice effects on both the old and new tests. (Author/BS)