Applies Kuhn's model of the structure of scientific revolutions, Popper's hypothetic-deductive model of science, and Lakatos' methodology of competing research programs to a historical biological episode. Suggests using Kuhn's model (emphasizing the nonrational basis of science) and Popper's model (emphasizing the rational basis of science) in…

Provides safety considerations related to chemistry experiments and demonstrations. Includes procedures for a volcano demonstration (which does not use ammonium dichromate) and three clock reactions, a list of hazardous chemicals, and a list of questions to help decide whether the risk of an experiment is acceptable for a class. (JN)

Discusses the air resistance on projectiles, examining (in separate sections) air resistance less than gravity and air resistance greater than gravity. Also considers an approximation in which a trajectory is divided into two parts, the first part neglecting gravity and the second part neglecting the air resistance. (JN)

Develops the concept of energy without using the terms heat and work. Topic areas considered include mechanical energy, internal energy, total energy, energy conservation, applications of energy conservation, kinds of internal energy, and restrictions on energy changes. Implications for teaching the energy concept are also considered. (JN)

Repetition of a historical experiment in a school project threw new light on the question of absolute rest. The student experiment investigated whether a particular direction in space could be singled out by a purely terrestrial procedure, while the original experiment investigated the drag coefficient of a solid medium. (JN)

Discusses the nature and role of models in various aspects of the chemistry curriculum, examining the purposes and importance of tangible, linguistic, arithmetical, thermodynamic, and quantum-physical models. Strategies in using models in laboratory work and in lecture demonstrations are also considered. (JN)

Describes a course designed to give high school physics teachers the confidence and the tools necessary to teach physics. This course used traditional high school physics textbooks and followed a typical high school physics course format. (JN)

Students at Jones Middle School (Upper Arlington, Ohio) became involved when a nearby radio telescope was threatened by a land sale. Students not only learned about the basics of telescope use but also wrote to various local and national officials to "save the telescope." (DH)

The ratio factors approach involves recognizing a given fraction, then multiplying so that units cancel. This approach, which is grounded in concrete operational thinking patterns, provides a standard for science ratio and proportion problems. Examples are included for unit conversions, mole problems, molarity, speed/density problems, and…

Rather than memorize numbers for sidereal periods of planets (time to orbit the sun), students can learn to determine these times through simple calculations. Comparison of a planet's synodic period to earth's year of 365 days is made, then multiplication to derive a full circle of 360 degrees establishes the sidereal period. (DH)

Thin slices of potato can be used to demonstrate the presence of protein, carbohydrates, and nucleic acids at the cellular level. Procedures and materials are provided for these simple tests. Also indicates that the presence of fat can be readily seen by staining avocado with Sudan red or Sudan black. (Author/DH)

Developed and validated a learning hierarchy for the concept "food web" (the hierarchy consisting of nine skill areas). Also investigated the misconceptions of 200 students related to these nine areas. Suggestions for applying the hierarchy model to remediation and resolution of the misconceptions are provided. (DH)

Investigated the meaning that Hindi-speaking students (N=826) in India and English-speaking students (N=1,635) in Tasmania preferred when thinking about each of 16 key concept definitions associated with the theme "the nature of matter." Results show marked changes in the development of these preferences which raises issues for science…

Suggests that electronics be taught using a systems approach, although this reverses the order of stages in the traditional approach by studying complete systems first. Also describes the hardware needed to implement a systems approach and the four stages of a course in which the equipment is used. (JN)

Discusses the nature of pseudoforces in accelerated frames of reference, providing examples related to the motion of a falling body and the toppling of an accelerated block. (JN)