Lists causes of freshwater supply depletion and successful reclamation projects including Imperial Dam in California, desalination in Arizona, and dual water supply in Florida. A national water policy is advocated. (DH)

Describes a qualitative analysis laboratory in which students examine specific precipitates that can be used to identify copper, cobalt, nickel, and iron cations. The objective of the laboratory is to determine which test or sequence of tests unambiguously identifies each cation and to use the results to identify several unknowns. (JN)

Presents information that gives a methodological background to the concept of food webs. Stresses the importance of calibrated techniques in ecological research and explains direct methods for studying animal diets. Exercises for gathering first-hand data on bird diets and analyzing secondary data on mammal diets are suggested. (ML)

Reviews methods of estimating pollen and seed dispersals and discusses the extent and frequency of gene exchange within and between populations. Offers suggestions for designing exercises suitable for estimating dispersal distances in natural plant populations. (ML)

Discussed are the basic and specialized skills needed for graphing exercises. Suggests approaches and activities that can be used in the teaching of graphing skills. Includes a listing of software programs for both teaching graphing and for analyzing data. (ML)

The easily obtained common snail shows interesting dietary preferences which can be the source of several simple experiments. Specific student instructions are given for quantitative and comparative studies using cabbage, lettuce, carrot, rutabaga, and onion. Suggestions for laboratory setup and further work are included. (DH)

The actual and preferred students' perception of classroom learning environment was measured using a modified Hebrew version of the Learning Environment Inventory (LEI). This (validated and analyzed for reliability) was given to chemistry (N=1080) and biology (N=400) students. Results and implications are discussed. (Author/JN)

Suggests mural ecology as an alternative to studying other habitats, providing examples of zonation patterns, food webs, effects of physical factors, and influence of man on mural communities. Also suggests incorporating these topics into ecology courses, offering ideas for field work and comparing mural to traditional ecological studies.…

Reports results from the International Chemistry Olympiad where a student from the United States won a gold medal for the first time. The Olympiad seeks to identify the best high school chemistry students in the world. (JM)

Examines factors affecting attitudes toward laboratory chemistry. Subjects (N=1638) were grade 11 chemistry students in 78 schools in rural, suburban, and urban Oyo State, Nigeria. Data indicate that students' attitudes toward chemistry as a subject is the most important determinant of the attitude toward the laboratory. (JM)

Proposes that the concept of evolution be used to integrate and link topics in biology syllabi. Justifies and cites advantages of teaching biology from an evolutionary viewpoint, providing specific examples of implementation possibilities. (ML)

Describes an exercise in which students calculate distances and heights from a single aerial photograph. The exercise (which does not require stereo photographic pairs) is adaptable to any aerial photograph for which the flight height, focal length, and photo center are known. (JN)

Reports on a longitudinal study of retention of science learning carried out in Israel (from grade 8 to grade 10, ages 13-16). Findings show that retention of meaningful school materials does exist from one course to another, even over relatively extended materials. (JN)

Explains the principles of the science of motion and examines Thomas Kane's deductive approach to the study of dynamics. Also recounts Kane's advances in explaining classic mechanics and discusses the advantages of his methods in the formulation of equations of motion and in applications to space technology. (ML)

Presents two scenarios to illustrate the difference between liability and negligence. Also presents highlights of four actual cases related to laboratory security, appropriate facilities, proper instructions, and protective gear. (JN)