Every measurement in science, every experimental decision, result and information drawn from it has to cope with something that has long been named by the term "error". In fact, errors describe our limitations when it comes to experimental science and science looks back on a long tradition to cope with them. The widely known way to cope…

Discusses the potential use, by students in cell biology and plant physiology, of isolated chloroplasts for determining the Emerson enhancement effect. The experiment designed to measure spectrophotometrically the photoreduction of a dye by illuminating chloroplasts with short- and long-wavelength light is presented. (HM)

Traces the development of college physics laboratories. Discusses the motivating forces that produced these laboratories, sources of experiments and the first and most influential laboratory manual prepared by E. C. Pickering for use at the Massachusetts Institute of Technology. (JN)

Describes a project to produce a series of laboratory manuals and instructional materials in which nuclear experiments are presented for the undergraduate advanced laboratory. The manuals are being compiled in the areas of physics, chemistry, geology and environmental sciences. (BR)

The impact of instructional television and educational reform in El Salvador was apparent in the 1969 school year. Large gains in learning were recorded for each of the three televised seventh-grade courses--science, mathematics and social studies. Baseline tests administered in four grades of school revealed that urban students developed…