Discusses the validity of studies of Spanish pronunciation in terms of research methods employed. Topics include data collection in the laboratory vs. in a natural setting; recorded vs. non-recorded data; quality of the recording; aural analysis vs. spectrographic analysis; and transcriber reliability. Suggestions for improving data collection are…

Outlines procedures for demonstrating and preparing a permanent slide of sister chromatid exchanges and recombination events between the two chromatids of a single chromosome. Provides the name of an additional resource for making preparations of exchanges. (RT)

Presents a laboratory exercise that uses a simple imaging technique to illustrate the profound effects that living roots exert on the pH of the surrounding soil environment. Achieves visually stimulating results that can be used to reinforce lectures on rhizosphere pH, nutrient availability, plant tolerance of soil acidity, microbial activity, and…

Describes a laboratory method to allow students to complete electrophoresis and staining of DNA samples within 1 45-minute classroom period. (MKR)

Describes the use of a digitized video image system in conducting radically different projectile experiments. Presents a detailed example of its use and discusses the advantages and disadvantages of using digitized video images. (JRH)

Describes an experiment that uses the ultrasonic transducer for demonstrating the Fourier components of waveshapes such as the square and triangular waves produced by laboratory function generators. (JRH)

Describes an experiment designed to help understand the effect of the curvature of the laboratory equipment support (cylindrical rod instead of knife-edge) on the frequency of oscillation of pendula. (ZWH)

Involves students in a study designed to examine the interaction between children's observations of light and shadows and their developing theories in the context of a series of lessons in a third-grade classroom. Results suggest that student's observation of light led to the development of a limited theory about light that was largely useful in…

Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

Discusses doing science experiments on a small scale in order to reduce the quantity of chemicals used in science classes. (MKR)

Presents food science experiments designed for high school science classes that aim at getting students excited about science and providing them with real-life applications. Enables students to see the application of chemistry, microbiology, engineering, and other basic and applied sciences to the production, processing, preservation, evaluation,…

Performed a variance analysis of the relation between the amount of time students spend experiencing hands-on science and science achievement. Reports that students who engaged in hands-on activities frequently scored significantly higher on a standardized test of science achievement than students who did not. (Author/JRH)

Presents experiments that use Microcomputer Based Laboratory (MBL) techniques to enable freshmen physics students to investigate complex systems, such as nonlinear oscillators or coupled harmonic oscillators, at a level appropriate for an independent project. (JRH)

Presents an example involving the metabolism of carbohydrates by microorganisms that provides results that contradict the generally speculated outcome, which is not an unusual situation in many scientific investigations. (JRH)