A decision field theory is proposed and used to explain motivational and cognitive mechanisms that guide the deliberation process involved in decisions made under uncertainty. Decision theories are extended into the stochastic-dynamic category. The proposed theory is compared with four other theories of decision making under uncertainty. (SLD)

Observes that the envelope theorem, a fundamental tool in duality analysis, is still a puzzle to many people. Argues that the essence of a solution proposed by Paul Samuelson (1947) is also unclear to many people, but can be communicated with a simple cost diagram. Presents and explains the proposed diagram. (DSK)

Presents an activity in which students propose that apples change their color as they ripen. Students gain content knowledge about decomposition, the growth of living mold, and the life cycle of fruit flies through purposeful inquiry connected to previous knowledge. (ASK)

Presents an activity in which the subject is the identity of the team in the greatest jeopardy of becoming the big loser in a basketball tournament. Explores several facts about the big loser, offering them in a hierarchy appropriate for creating various short- and long-term projects for a high school mathematics class. (ASK)

Another Rasch approach to the measurement of change, the multidimensional random coefficient multinomial logit model (MRCML), is proposed. The MRCML model can be applied to polytomous items and the investigation of variations in item difficulties. Some simulation studies demonstrate good parameter recovery for the MRCML model under various testing…

The effects of levels of aggregation on measures of goodness of fit and higher order parameter estimates obtained from confirmatory factor analysis (CFA) were investigated using three indexes of fit and data on the academic self-concept of 270 undergraduates. Implications of results for model complexity in CFA are discussed. (SLD)

A generalization of the single trait, multioccasion measurement model is provided through a confirmatory measurement model for multitrait-multioccasion (MTMO) data. Several commonly used confirmatory measurement models are contrasted with the MTMO, and it is illustrated with a large four-wave dataset on family support and alcohol involvement. (SLD)

Whether the one- or two-factor Wechsler or weighted sum scores (WSS) structural models adequately fit the Wechsler Intelligence Scale for Children III (WISC-III) covariance matrices was studied with samples of 2200 and 1118 children from previous studies. Both the WSS and supplemented models provided better fit than Wechsler's model but still…

Examines education's effects on choice of medical care inputs and the subsequent relationship between these inputs and overall health. Specifically examines consumption of curative and preventive medical care and other lifestyle choices, using nultivariate analysis of three estimation models and 1987 National Medical Expenditure Survey data.…

Describes an experiment using applications and projects to motivate students in college algebra. Provides a few illustrative examples of the applications/projects used and shares some student comments. (Author/ASK)

Discusses some aspects of learning to read the process of the variation in congruence and relate it to the original geometry of the sphere since it touches on more general questions about how models are appropriated and used. Presents a learning episode that implemented projective models for both spherical and hyperbolic geometry in Object Logo.…

Illustrates the use of latent growth modeling (LGM) as an analytical tool in program evaluation using the hypothetical example of a high school drug prevention program. Demonstrates the use of LGM in assessing longitudinal impact and in incorporating predictors of status and growth into a model. Highlights advantages and limitations of LGM. (SLD)

Discusses a precalculus project in which students create a model United Nations to present and discuss the long-term prognosis for individual countries given data on population growth and food production. Students compare exponential and linear functions to determine whether starvation will occur and prepare oral and written presentations of their…

Illustrates how modeling and other non-deductive forms of reasoning as employed by a highly creative mathematician can be productive as important conceptual innovations and, by the same token, can serve as effective tools for stimulating conceptual development in the process of learning mathematics. Characterizes Klein's model-based practice and…

Provides asymptotic formulas for the standard errors of parameter estimates from the NOHARM computer program for restricted and unrestricted rotated models, using large-sample theory, and a goodness-of-fit test of the model. Used simulation to show that results from NOHARM are comparable to the three-stage estimator of B. Muthen (1993). (SLD)