This study examines whether the classification and regression tree (CART) model improves the early identification of students at risk for reading comprehension difficulties compared with the more difficult to interpret logistic regression model. CART is a type of predictive modeling that relies on nonparametric techniques. It presents results in…

Early in their study of one-dimensional kinematics, my students build an algebraic model that describes the effects of a rolling ball's (perpendicular) collision with a wall. The goal is for the model to predict the ball's velocity when it returns to a fixed point approximately 50-100 cm from the wall as a function of its velocity as it passes…

This article describes an empirical study concerning the mastering of the chemical equilibrium concept by prospective physical sciences teachers. The main objective was to check whether the concept of chemical equilibrium had become an integrating and unifying concept for them, that is to say an operational and functional knowledge to explain and…

A few kilometers from the shores of Palm Beach County, Florida, is the Gulf Stream current--a remarkable "river" within an ocean. The current's journey across the Atlantic Ocean connects southeast Florida and southwest Great Britain as it streams steadily north at speeds of 97 km a day; moving 100 times as much water as all the rivers on…

Describes features of a macroeconomics model that runs on a microcomputer and its solution, sometimes called a simulation. Specific uses of the model in the teaching of introductory and intermediate/advanced levels of macroeconomics are discussed, as well as use by economic planners in running alternative forecasts. (MBR)

Describes activities in which students: (1) propose creative atomic models that account for observed properties and predict additional experimental data; (2) calculate empirical formulas for 27 binary compounds; (3) propose a model to explain why certain elements have certain valences; and (4) arrange hypothetical elements into a periodic chart.…

Describes a sustainable planet index (SPI) to gauge the survivability of the earth ecologically and economically. Compares the SPI to the consumer price index and general business cycle theory from which it draws constructs. Suggests that the SPI exhibits properties of a sine wave and is useable in mathematical formulations, explanation, and…

Two activities in which students use the human body to collect meaningful data that will be used symbolically in the form of sets of equations to search for patterns in nature are described. The mathematics and science concepts/skills, background information, objectives, lesson outline, and extensions are included. (KR)

Most constructive critics of education agree that today's students are better than any in United States history. Yet problems like competency shortages and outmoded curricula remain. When schools were basically "socializers" (1885-1957), praise outstripped criticism--until 1957's Sputnik. In response, Congress initiated the National Aeronautics…