Emphasizes a real-world-problem situation using sine law and cosine law. Angles of elevation from two tracking stations located in the plane of the equator determine height of a satellite. Calculators or computers can be used. (LDR)

The application of time series analysis is described, focusing on the use of regression analysis for analyzing time series in a way that may make it more readily available to an evaluation practice audience. Practical guidelines are suggested for decision makers in government, health, and social welfare agencies. (SLD)

An eclectic approach is presented for the evaluation of services to the homeless. The method combines social network analysis and multiattribute technology to allow for development of a criterion for evaluation of services for a geographic area. Service delivery configuration, evaluation criteria, and a planning and monitoring strategy are…

Evidence is presented on the generalizability and convergent validity of performance assessments using data from six studies of student achievement that sampled a wide range of measurement facets and methods. Results at individual and school levels indicate that task-sampling variability is the major source of measurement error. (SLD)

Presents a methodology of mathematical and technological principles as integrated components of the Design and Technology syllabus of the National Curriculum in the United Kingdom. The methodology is based on the syllabus area of product analysis and employs a structured problem-solving approach. (ASK)

Estimates earnings reported by 219 recent college graduates and earnings expected by 248 college seniors, considering seven variables. Although students' expectations generally accord with recent graduates' marketplace experiences, students underestimate the earnings outcome of working more hours and overestimate age effects. The model holds truer…

Drawing on empirical studies from five countries (Netherlands, Spain, Portugal, United Kingdom, and United States), over 2 decades, outlines irregularities in the incidence of over- and under-education and consequences for individual earnings. The overall incidence of overeducation in the labor market is about 26 percent. (Contains 33 references.)…

Develops a model of the child-care environment, concentrating on how child-staff ratios, group size, and caregiver ability influence amount of time children spend on-task and intensity of caregiver-child interactions. The model clarifies these variables' roles and explains regulation's potential costs and benefits. Regulation alone cannot improve…

Explores the strategies used by prospective secondary mathematics teachers (N=13) to develop and validate functions as mathematical models of real-world situations. Uses a grounded hypothesis on strategy selection. Concludes that strategy choice was influenced by task characteristics and interactions with other student modelers. Contains 38…

Develops an empirical model for heterogeneous human capital investment decisions, using survey data from a cohort of Dutch workers. Applies the model to investment in three forms of enterprise-related training: technical, economic-administrative, and other. Results show that technical training yields the lowest wage gain, while other…

Presents a mathematics activity to model the exponential growth of the common cold, AIDS, or any other communicable disease. Underscores the effect that a friend's or partner's previous behavior may have on a current relationship and on society at large. (ASK)

Theorem acquisition and deductive proof have always been core elements in the study and teaching of Euclidean geometry. The introduction of dynamic geometry environments, DGE (e.g., Cabri-Geometre, Geometer's Sketchpad), into classrooms in the past decade has posed a challenge to this praxis. Students can experiment through different dragging…

Generalizing or making claims that extend beyond particular situations is a central mathematical practice and a focus of classroom mathematics instruction. This study examines how aspects of generality are produced through the situated activities of a group of middle school mathematics students working on an 8-week population-modeling project. The…

Building Blocks is a National Science Foundation-funded project designed to enable all young children to build a solid foundation for mathematics. To ensure this, we used a design and development model that drew from theory and research in each phase. Our design process is based on the assumption that curriculum and software design can and should…

Cox (1972) proposed a discrete-time survival model that is somewhat analogous to the proportional hazards model for continuous time. Efron (1988) showed that this model can be estimated using ordinary logistic regression software, and Singer and Willett (1993) provided a detailed illustration of a particularly flexible form of the model that…