Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

Describes how to organize a student-directed laboratory investigation which is based on amphibian metamorphosis, lasts for nearly a term, and involves extensive group effort. Explains the assignment, student response and opinion, formal paper, and instructor responsibilities. (RT)

This article presents a variety of topics discussed in this column and at a biology teachers' workshop concerning the quality and value of lab techniques used for teaching high school biology. Topics included are Drosophila salivary glands, sea urchins, innovations, dyes and networking. (CW)

Provided are background information, equipment lists, and procedures for four activities for teaching aquatic ecology. Activities include "The Aquatic Food Chain Game"; "Two-Liter Aqua-Vivariums"; "A Sealed World"; and "Weaving a Web: Evaluation." (CW)

Three articles focus on many classroom activities and experiments inspired by the voyage of two canoes, built of traditional materials, from Hawaii's Hilo Harbor in 1995. Nationwide, students followed daily satellite tracking, accessed the Internet for updated accounts of the canoes, talked directly with navigators, and watched television…

Describes problems in teaching problem solving and summarizes research in this area. Presents Guided Design or Guided Decision Making as a problem-solving approach in which groups of students work their way through a model of the problem-solving process as they wrestle with a discipline-specific situation. (PR)

Provides a student worksheet and set-up instructions for a science experiment to demonstrate the concept of density. Students are asked to explain the phenomenon in which a liquid of lower density placed in the bottom of two vertical flasks flows up to replace the liquid of higher density in the upper flask. (MDH)

Presents an activity to help students understand the precepts of the Hardy-Weinberg principle and simultaneously permit observation of a model of evolution through natural selection in a nonthreatening setting. (PR)

Presents a simple activity designed to allow students to experimentally verify Kepler's second law, sometimes called the law of equal areas. It states that areas swept out by a planet as it orbits the Sun are equal for equal time intervals. (PR)

Presents information and data on an experiment designed to test whether different atmosphere compositions are affected by light and temperature during both cooling and heating. Although flawed, the experiment should help students appreciate the difficulties that researchers face when trying to find evidence of global warming. (PR)

Probeware is increasingly being implemented in science classrooms because it is less expensive than it used to be and improvements in hardware and software have made it more accessible to students and teachers. Many probes or sensors can now simply be connected to a computer, calculator, or other handheld device, and will immediately begin to…

Although ammeters are very important tools for science classes in elementary and junior high schools, many ordinary ones are not easy to handle nor sufficiently educational. From this viewpoint, the authors have investigated the possibility of using clamp-on ammeters, which are very common among professional electricians, for educational purposes.…

Computer interfaced electrostatic charge sensors allow both qualitative and quantitative measurements of electrostatic charge but are quite sensitive to charges accumulating on modern synthetic materials. They need to be used with care so that students can correctly interpret their measurements. This paper describes the operation of the sensors,…

In the framework of a curriculum reform in the Netherlands, an interdisciplinary open inquiry assignment has been introduced as a part of the final secondary school examinations. We developed and evaluated a preparatory open inquiry assignment to be used in science and mathematics departments of schools, in collaboration with each other: the…

The Zimbabwe Secondary School Science Project (ZIM-SCI) developed student study guides, corresponding teaching guides, and science kits for a low-cost science course which could be taught during the first 2 years of secondary school without the aid of qualified teachers and conventional laboratories. This teaching guide, designed to be read in…