Described is a LOGO computer program that enables students to investigate the relationship between a digital number and the resistance in a variable resistor used to generate that number. Likewise, actual temperature readings and the corresponding resistance within a thermistor can be used for data gathering and subsequent analysis. (JJK)

Seven qualitative issues associated with randomization that have the potential to weaken or destroy otherwise sound experimental designs are reviewed and illustrated via actual field experiments. Issue areas include ethics and legality, liability risks, manipulation of randomized outcomes, hidden bias, design intrusiveness, case flow, and…

A simple experimental arrangement that makes it possible to simultaneously observe and compare on a screen the two interference patterns produced by reflected and transmitted light from incident white light impinging on a soap film directly is described. Procedures and illustrated effects are discussed. (CW)

Two experiments which can be used to illustrate light diffraction using compact disks are detailed. Included are procedures, computations, and probable results. (CW)

Describes the use of practice weighings and handling of fluorescent compounds to assist in teaching students safe-handling techniques. (PR)

Describes the prosecution efforts regarding a chemistry teacher when one of the teacher's students was injured in an explosion in an attempt to make gun powder. In a different section, discusses nonscientists in science laboratories and the responsibilities of competent persons. (PR)

Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

Describes experiments with chewing gum for students to learn about the scientific method. Students classify various types of gum and then do a self-designed consumer product test. (PR)

Describes science experiments for undergraduate biology instruction on the concepts of mutation and characterization of the resulting mutant strains. The filamentous fungi "Fusarium moniliforme" is used to illustrate the induction of mutants (mutagenesis), identification of the mutated gene, construction of a biochemical pathway, and…

Provides instructions to construct a device that measures air pollutant concentrations using an inexpensive modified portable aerator. Describes sampling strategies by which students examine the concentrations of pollutants in school and industrial settings. (MDH)

Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

Describes an experimental system that allows students to observe pollen tubes in vitro and to investigate a variety of aspects of pollen tube-style interactions. One interaction provides an example of postmating reproductive isolation. (MDH)

Shows how fruit flies can be used in the teaching genetics laboratory to correlate the principles of heredity with the modern understanding of enzymes. (Contains 16 references.) (MDH)

Describes an activity for helping students understand and use data tables. (PR)

Describes making a magnetic pendulum similar to those seen in novelty shops. Presents an open-ended activity and a more structured activity using this pendulum. (PR)