Two experiments with pigeons examined the effects of unsignaled, nonresetting delays of reinforcement on responding maintained by different reinforcement rates. In Experiment 1, 3-s unsignaled delays were introduced into each component of a multiple variable-interval (VI) 15-s VI 90-s VI 540-s schedule. When considered as a proportion of the…

Extracting and applying lessons from history is rarely easy and sometimes risky but there are moments when historical records are so compelling that they rise above mere proof to the level of interocular impact. In this article, the author shares his similar experience while visiting his colleague, Professor Bruce Clark, at the University of…

An effective way to teach the concept of image is to give students a model of human vision which incorporates a simple mechanism of depth perception. In this study two almost identical versions of a curriculum in geometrical optics were created. One used a mechanistic, interpretive eye model, and in the other the eye was modeled as a passive,…

Benjamin Franklin was the first great American scientist. This book contains activities which are organized into six subjects that Benjamin Franklin investigated: observation and experimentation, meteorology, electricity, sound and music, paper and printing, and lenses and vision. At the end of each chapter is a list of resources and ideas. The…

This book contains 25 experiments designed to help students understand some of the science used every day. Each experiment includes a list of materials, a series of easy-to-follow steps, an explanation of the scientific principle demonstrated, and additional scientific facts and information. No special or expensive materials are required.…

This document is designed to provide practical information for teaching the Physics 20-30 Program of Studies. The first section provides an overview of Physics 20, explaining the program philosophy and the selection and sequencing of topics. The use of concept connections and teaching a course around the science themes are described, as well as…

Describes how to construct a traffic light device for use in teaching about wavelengths in physics. (LS)

Describes differences in the construction of a colorimeter and a photometer. Gives examples of ways in which light-measuring instruments can be used by biologists. These examples can be used either as class experiments or as individual projects. (GS)

An approach which is designed to help students better understand the utility of models in understanding and doing physics, specifically in a course in light and color, is described in this paper. Explanations are given and illustrations are provided of an analogue model of waves which assist in the creation of an abstract model to deduce Snell's…

Describes a number of activities designed to assist student understanding of the phenomenon of light bending when it passes from one meduim to another. (JR)

Describes a series of optical illustions designed to explore the nature and behavior of light, the mechanics and optical principles of eyes, and the brain's learned ability to interpret what we see. (BR)