A comparison of the physics concepts explanations of ninth graders and of physics graduates and graduate students found that physics novices were strongly inclined to conceptualize physics concepts as material substances, whereas experts' protocols revealed distinctly nonmaterialistic representations. (MDM)

Describes the brake sensors and the essential elements of a differential in explaining how antilock braking systems (ABS) function. (MVL)

Discusses Bernoulli's equation with regards to: horizontal flow of incompressible fluids, change of height of incompressible fluids, gases, liquids and gases, and viscous fluids. Provides an interpretation, properties, terminology, and applications of Bernoulli's equation. (MVL)

Discusses five problems concerning Newton's law of universal gravitation. Provides detailed answers to each question. (MVL)

Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

Discusses a well-known optical refraction problem where the depth of an object in a liquid is determined. Proposes that many texts incorrectly solve the problem. Provides theory, equations, and diagrams. (MVL)

Describes how liquid nitrogen is attracted to the poles of neodymium magnets. Nitrogen is not paramagnetic, so the attraction suggests that the liquid nitrogen contains a small amount of oxygen, which causes the paramagnetism. (MVL)

Combined free response questionnaire and interview procedure are used to probe students' ideas regarding how they believe they see both luminous and nonluminous objects and how they think they hear source of sound. From large sample of students studied (n=1901), prevalence of ideas in different age groups is compared, and progression can be seen.…

Discusses the meaning of velocity in the Lorentz force law and to what the velocity of the charge is relative. Provides a brief summary of the history of the magnetic force. (23 references) (MDH)

Authors describe some alternative conceptions held by Portuguese physics students about mechanics and compare students' scientific conceptions with the evolution of historical ideas. Authors contend that teacher knowledge about the history of science can facilitate teaching for conceptual change in physics. (over 20 references) (Authors/PR)

This paper describes the current approach used in Israel for teaching photosynthesis to junior high school students. Authors identify two types of problems, psychological and instructional, that children experience in understanding photosynthesis. Presents a foundation and sequence for a new approach to teaching photosynthesis. (18 references) (PR)

The carpel is a highly modified leaf enclosing the ovules. This article describes methods for teaching about the evolution of the carpel and the nature of carpel fusion. Presents an illustration of the evolution of the most common types of compound pistil arrangement from the ancestral single-carpel marginal type of placentation. (PR)

This research used semistructured interviews to investigate students' (n=32) understanding of electrochemistry following a 7-9 week course of instruction. Three misconceptions were identified and incorporated with five previously reported into an alternative framework about electric current involving drifting electrons. Also noted was the tendency…

Fifteen true-false statements are provided that are to be used to spur discussion and arguments about the concept of motion. Each statement is carefully worded to sound plausible, but each one attacks some misunderstanding common to students who are encountering Newton's mechanics for the first time. (KR)