A general approach to analysis of covariance structures is considered, in which the variances and covariances or correlations of the observed variables are directly expressed in terms of the parameters of interest. The statistical problems of identification, estimation and testing of such covariance or correlation structures are discussed.…

Some activities designed around the Monte Carlo method of solving probability problems are described. The instructional applications of this method involve physical models or simple BASIC computer programs. (MP)

Explains some observed library circulation frequency distributions through use of a simple stochastic model for the borrowing of books from a library collection. Parameters of the model are described and the model is applied to circulation data from three academic libraries. (Author/SW)

Three models to predict future world records for footraces are reviewed. The records for the mile run are presented with time and year given in linear, hyperbolic, and experiential relationships. (MP)

Decision-making processes were investigated in a laboratory analogue of clinical diagnosis and through computer simulations of decision making. The data indicated that nonprobabilistic theories can provide plausible and complete accounts of decision behavior and can improve quantitative accuracy of predictions that are based on traditional…

Catastrophe theory, a mathematical technique for studying discontinuous processes such as sudden and dramatic changes in the behavior of a system as a consequence of small changes in controlling factors, is discussed. The "cusp catastrophe" is used to create a three-dimensional model. (Author/MLW)

The use of saltine crackers to illustrate whole numbers, decimal fractions, common fractions, percents, money, and other mathematical concepts is reviewed. (MP)

Presents a mathematical model that will help students explore concepts related to population growth such as doubling time, replacement level and zero population growth. (Auth/WB)

A description is given of a course developed (at Oklahoma State University) to provide practical skills for mathematics majors entering industry instead of academia. (MK)

Macready and Dayton introduced two probabilistic models for mastery assessment based on an idealistic all-or-none conception of mastery. Alternatively, an application of latent trait theory to mastery testing is proposed (a three parameter logistic model) as a more plausible model for test theory. (Author/CTM)

Analyzes the use of weights to denote a query representation and/or the indexing of a document as a generalization of a Boolean retrieval system. Criteria are given for the functions used to evaluate the relevance of the records to a specific query and a new evaluation approach is suggested. (CWM)

Presents a new method of document retrieval based on the fundamental operations of fuzzy set theory. Basic notions are introduced. Then the syntax and semantics of the proposed language for document retrieval is given, and an algorithm allocating documents to particular queries is described and its properties are discussed. (Author/CWM)

Instructional problems springing from teachers' incorrect use of mathematical models during the initial development of ideas and processes are analyzed. Examples of models for subtraction and division are given, and their appropriate use discussed. (DT)

Discusses the benefits of dynamic geometry software in helping students learn to write proofs. The software allows students to create simple geometric figures, explore relationships, make conjectures about their properties, and test those conjectures. (AIM)

Explains an approach to teaching dimensional analysis that differs slightly from the traditional approach. The difference lies in the novelty of exposition in the presentation and interpretation of dimensional analysis as a speculative process. (DDR)