Applies the confluence model to a longitudinal intact family data set. Also tests the data with simple linear models. Results suggest that the confluence model should be rejected as a useful model for these data based on principles of parsimony and predictability. (Author/AS)

A computer program is presented which simulates the classical probability machine, using Applesoft II high-resolution graphics. Many variables are left to the user's choosing. Suggestions for using the machine, understanding the problem, the mathematical model, and further program documentation are given. (MNS)

Estimation is by means of iterative convergence to maximum likelihood estimates, and two approaches to assessing fit of the model to sample data are discussed. Relation of this general probabilistic model to other, more restricted models is explored and three cases of the general model are applied to exemplary data. (Author/RC)

Context for the application and specialization of a Bayesian linear model is m-group regression and the application to the prediction of grade point average. Specialization involves the assumption of homogeneity of regression coefficients (but not intercepts) across groups. Model's predictive efficiency is compared with that of the full m-group…

The average workweek of full-time workers declined by 35 percent between 1900 and 1940, but has not changed significnatly since then, and the secular rigidity of the full-time workweek remains. An expanded model which incorporates the effects of growth in education and in the female wage explains the post-1940 secular trend. (Editor/HD)

Calculations of storage requirements for retrieval systems using inverted files. Problem of minimal storage requirements for inverted file is solved for different index term distributions. (Author/KP)

Analyzes the impact of expenditures per year of schooling on earnings, based on data from a longitudinal study of 1,633 male American World War II veterans. (Available from North-Holland Publishing Company, P.O. Box 211, Amsterdam, the Netherlands; $13.50 annually, plus $4.00 postage and handling) (JG)

In its empirical part this paper establishes a general weak understanding of the process of applying a mathematical model. This is also evident in the way teachers regard the application of alternative sharing in their own problem solving and in relating to children's answers. The theoretical part analyses problems that are considered as…

This paper briefly reviews research grounded in cultural and socio-constructivist theories carried out to investigate the phenomenon of suspension of sense-making when doing school arithmetic word problems. It begins with ascertaining studies documenting and marking out the phenomenon, then provides an explanation of the observed effects that are…

The integration of History in the educational practice can lead to the development of a series of activities exploiting genetic "moments" of the history of Mathematics. Utilizing genetic ideas that developed during the 14th century (Merton College, N. Oresme), activities are developed and mathematical models for solving problems related to uniform…

In this study I examined 19 preservice secondary mathematics teachers' solution processes to word problems for which the subtraction or addition of the two given numbers yields 1 more or 1 less than the correct solution. Among the aspects of their solution processes that were examined are: the modeling strategies, the type of errors, and the…

This collection of activities is intended to enhance the teaching of college algebra through the use of modeling. The problems use real data and involve the representation and interpretation of the data. The concepts addressed include rates of change, linear and quadratic regression, and functions. The collection consists of eight problems, four…

In this paper we analyze the meanings of the "equal" sign as generated by sense production of the methods of substitution and comparison for solving problems and systems of equations of two unknowns. These methods are usually introduced through an extension process of the syntax and meanings recently learned by students in order to solve…

This paper discusses the application of Hierarchical Linear Modeling (HLM) to the evaluation of the effectiveness of Basic Skills programs in the Newark (New Jersey) school district. Whether HLM is able to handle regression effects in Basic Skills examination data is studied. The analysis uses data from the Stanford Achievement Tests for…

This technical report provides an updated assessment of the problem of optimizing the periodicity of the Schools and Staffing Survey (SASS). Making use of data from three rounds of SASS data collection (for school years 1987-88, 1990-91, and 1993-94), the report extends and updates the preliminary findings and interim assessments that were…