Analyzes the allocation of student time from the perspective of economic theory with an economic model that predicts a small increase in educational achievement relative to substantial increases in instructional time. Predictions are supported by empirical evidence. Policy consequences are examined. (MLF)

In an experiment manipulating artificial data in a factorial design, model misspecification and varying levels of error in measurement and in model structure are shown to have significant effects on LISREL parameter estimates in a modified peer influence model. (Author/LMO)

Discusses the use of ratio diagrams, which plot the calculations of equilibrium concentrations of the species of the carbonate system. Provides examples to describe how these diagrams can be used to illustrate the behavior systems of interest in volumetric analysis, where absorption or loss of carbon dioxide takes place. (TW)

An activity involving the charting of the spread of a disease is described. Arrows are used to develop models of the progression of the disease. (MNS)

This paper applies a theory of growth in academic achievement to the study of the effects of ability grouping on reading achievement. The theory sees students' ability and effort determining how they utilize opportunities for learning provided by instruction. (Author/JAZ)

The potential value of developing item banks that would both guarantee the quality of teacher-made examinations and allow for national comparison of student achievement is described. Use of Rasch model methods, rather than classical item analysis techniques, to calibrate the items for these banks is illustrated. (BS)

Pennsylvania's mathematical modeling technique to evaluate tax reform proposals requires the following data: personal income at the local level and measures of the breakdown of property tax payment by land use classification. The simulation technique could be readily adapted in reorganizing educational finance systems. (MLF)

Research analyzing demand for librarians in public, school, academic, special libraries, and in nonlibrary information professions, indicates that from 1983 to 1990, there will be almost no additional positions in traditional areas. Replacement of librarians will generate 9,500 to 10,000 new jobs per year. Footnotes and 114 references are…

Applies an economic model of occupational supply to librarianship to develop models that explain determination of number of accredited M.L.S. graduates and their starting salaries. Models are used to project graduates and salaries through 1990, then extended to project additions to supply of librarians from all sources. (36 references) (EJS)

The causal relationship between metaphonological skills (sound blending and segmentation) and reading/spelling was investigated in two studies of first graders. One tested causal models using data from a longitudinal study of 46 dyslexics and 44 control children. The other studied the effects of metaphonological training versus general language…

A solution to the problem of specification error due to excluded variables in statistical models of treatment effects in nonrandomized (nonequivalent) control group designs is presented. It involves longitudinal observation with at least two pretests. A maximum likelihood estimation program such as LISREL may provide reasonable estimates of…

Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

Japanese lesson study, in various adapted forms, is becoming increasingly significant in professional development of mathematics teachers in the USA. Our goal in the research reported in this paper was to investigate, in a three-tiered teaching experiment, the cycles of learning of two researchers, six teachers, and the students in three grade 4…

Uses a model portraying school district decision makers as "consumers" to analyze fiscal strain's causes (enrollment decline, input price increases, and changes in input mix) as variants of the general consumer model. Measures the impact of each cause of fiscal strain and discusses implications for state and federal aid. (Author/RW)

Using an input-output framework, the author derives hypotheses on wage differentials based on the assumption that human capital (in this case, education) will explain workers' wage differentials. The hypothetical wage differentials are tested on data from the Italian economy. (RW)