Models are discussed both as concrete representations of mental constructs and as various manipulative devices. Illustrations of effective model use, suggestions for acquiring models, and lists of models for specific concepts are included. (LS)

Discusses methods of weighting of descriptors in document search patterns together with the concept of relative indexing and conditions which should be satisfied by descriptor weight. A procedure for modifiying document search patterns based on users' informational needs and opinions is outlined, and examples are given. Sixteen references are…

Discusses simulation program to aid in the design of enzyme kinetic experimentation (includes sample runs). Concentration versus time profiles of any subset or all nine states of reactions can be displayed with/without simulated instrumental noise, allowing the user to estimate the practicality of any proposed experiment given known instrument…

Discusses a mathematical model for mastery learning. The model includes measures of a motivational factor and the specific ability of a learner with respect to content being learned. The model also contains a variable reflecting prior learning. Assumptions/limitations are discussed, and research questions raised. (Author/JN)

Data from a 1974 national survey of blue-collar workers were used to test the effects of occupational hazards on health while controlling for earnings and schooling. Among the findings were that schooling has no effect on job health (hours lost while sick), either directly or indirectly through job choice. (Author/RW)

To examine the impact of enrollment shifts between public and private schools on public school expenditures per pupil, 1970-71 data were gathered on private school tuition and enrollment, public and parochial school expenditures, and demographic variables. Analysis using an economic model indicated few effects on public school expenditures. (RW)

This paper poses a research question about how a person's work experience affects his or her earnings and shows how the Cumulative Experience Method (CEM) can provide an answer to the question using all available information in a longitudinal data set. (Author/GDC)

A basic structure approach is proposed for obtaining multidimensional scale values for attitude, achievement, or personality items from response data. The technique permits the unconfounding of scale values due to response bias and content and partitions item indices of popularity or difficulty among a number of relevant dimensions. (Author/BH)

Differences in the value of unemployment insurance benefits alter the extent of job search activities by current recipients, according to this study, but differences in expected value of future unemployment benefits do not appear to affect the search process of those not currently eligible for payments. (MF)

Two simulations designed to teach probability to middle-school age pupils are presented. The first simulates the one-on-one foul shot simulation in basketball; the second deals with collecting a set of six cereal box prizes by buying boxes containing one toy each. (MP)

Describes a one-dimensional model for an ideal gas to study development of disordered motion in Newtonian mechanics. A Monte Carlo procedure for simulation of the statistical ensemble of an ideal gas with fixed total energy is developed. Compares both approaches for a pseudoexperimental foundation of statistical mechanics. (Author/JN)

Describes the use of a microcomputer in studying a model experiment (Brownian particles colliding with thermal particles). A flow chart and program for the experiment are provided. Suggests that this experiment may foster a deepened understanding through mutual dialog between the student and computer. (SK)

A model for research on teacher effects in which the variance in student outcome post-test performance is attributed to pre-test perfomance; to separate construct domains of student, instructional, and teacher variables; and to interactions between variables in these three construct domains is presented and tested. (Author/JKS)