A classroom activity analyzes the mathematics found in Shipwreck at the Bottom of the World, the true story of Ernest Shackleton and the 27-man crew who all survived a shipwreck at the South Pole. (Contains 3 figures.)

Many common objects can provide numerous opportunities for students to develop mathematical concepts and skills. The lesson described in this article provided an excellent opportunity for middle school students to discover how real-life situations do not always present obvious "right" answers. As students explored a question related to the…

This article describes a unit of instruction designed to promote a conceptual understanding of area in sixth-grade students. Students used benchmarks to estimate the areas of real houses and calculated the areas of houses based on building plans. (Contains 7 figures.)

Eighty college students read textbook passages that either included marginal inserts to signal key concepts or did not include these inserts. Signaling key concepts enhanced performance on content quizzes overall and on subsets of items assessing signaled material. Performance was not affected on subsets of items for nonsignaled content. Students…

This study investigates item parameter recovery, standard error estimates, and fit statistics yielded by the WINSTEPS program under the Rasch model and the rating scale model through Monte Carlo simulations. The independent variables were item response model, test length, and sample size. WINSTEPS yielded practically unbiased estimates for the…

Computer algebra methods based on results of commutative algebra like Groebner bases of ideals and elimination of variables make it possible to solve complex, elementary and non elementary problems of geometry, which are difficult to solve using a classical approach. Computer algebra methods permit the proof of geometric theorems, automatic…

The paper's aim is to note a remarkable (and apparently unknown) relation for right triangles, its generalisation to arbitrary triangles and the possibility to derive these and some related relations by elimination using Groebner basis computations with a modern computer algebra system. (Contains 9 figures.)

Objective: First, to provide information about best practices in handling missing data so that readers can judge the quality of research studies. Second, to provide more detailed information about missing data analysis techniques and software on the Journal's Web site at www.jaacap.com. Method: We focus our review of techniques on those that are…

Preference orderings among a set of options may depend on the elicitation method (e.g., choice or pricing); these preference reversals challenge traditional decision theories. Previous attempts to explain these reversals have relied on allowing utility of the options to change across elicitation methods by changing the decision weights, the…

Computation can have a profound intellectual impact, like the alphabet thousands of years ago. Using computation, people can begin to outline cognitive structures that will revolutionize the way they learn, although, especially at universities, the dreams must sometimes lag behind their potential due to limited funding. Ultimately, however, the…

This study examines one child's use of computational procedures over a period of 3 years in an urban elementary school where teachers were using a standards-based curriculum. From a sociocultural perspective, the use of standard algorithms to solve mathematical problems is viewed as a cultural tool that both enables and constrains particular…

The authors surveyed 738 college students aged 18 to 27 years to assess over weight, obesity, dietary habits, and physical activity. They used BMI (body mass index) [greater than or equal to] 25 kg/m[squared] or BMI [greater than or equal to] 85th percentile and BMI [greater than or equal to] 30 kg/m[squared] or BMI [greater than or equal to] 95th…

There is no common agreement on the meaning of the word "understand". However, there is agreement on what students should be able to do with material they understand. Bloom et al. discuss kinds of tasks a student should be able to do, provided that the student understands. In a similar way, Biggs and Collis provide a taxonomy intended to evaluate…

Unfolding response models, a class of item response theory (IRT) models that assume a unimodal item response function (IRF), are often used for the measurement of attitudes. Verhelst and Verstralen (1993)and Andrich and Luo (1993) independently developed unfolding response models by relating the observed responses to a more common monotone IRT…

This article addresses the validity of teacher evaluation measures produced by the Tennessee Value Added Assessment System (TVAAS). The system analyzes student test score data and estimates the effects of individual teachers on score gains. These effects are used to construct teacher value-added measures of teaching effectiveness. We describe the…