Discusses the various ways that time is measured and expressed, noting several discrepancies between descriptives and their respective vocabularies. Suggests that a logarithmic time scale be adopted by chemists (such as one used in the experimental sciences) particularly when addressing very fast processes. (TW)

Discusses the historical development of a new value of the second dissociation constant (K2) for hydrogen sulfide (H2S). Describes the differences between the traditional high values for K2. Suggests modification of teaching about sulfide equilibria in light of the new low value for K2. (TW)

Describes an instructional strategy based on the learning cycle for teaching the use of significant figures. Provides explanations of teaching activities for each phase of the learning cycle (exploration, invention, application). Compares this approach to teaching significant figures with the traditional textbook approach. (TW)

Discusses some of the difficulties in the measurement of pressure, including the use of open-ended and closed-ended manometers. Suggests the use of an analogy of a child's seesaw in teaching about manometers. Includes diagrams showing how various positions and weights on a seesaw compare with different pressure measurements. (TW)

Reports on a study done in Quebec, Canada, to determine the level of agreement or disagreement between principals and teachers using established criteria to measure the effectiveness of a science teacher. Results were used in an attempt to construct a profile of the attributes of an outstanding science teacher. (TW)

Reports on a study of the interactions of students in Australian high schools and was designed to focus on "target students" who monopolized whole class interactions. Students who were asked by teachers to be target students tended to have higher formal reasoning ability and achievement levels than the other students. (TW)

Presents two different approaches to teaching stoichiometry. One uses a question and answer technique and the familiar concepts of "pounds" and "degrees" to describe the concept. The second example introduces stoichiometric relationships used in the well-known camper's snack known as S'mores. (TW)

Discusses the goals of learning cycle laboratories in helping students acquire knowledge about a specific topic and to do so moving in a non-threatening way from the concrete operational level to the formal operational level. Describes an experiment designed for such laboratories dealing with the topic of oxidation-reduction. (TW)

Describes a British secondary school's use of a spectrometer to identify minerals. Discusses the origins of mineral spectra, the preparation of the specimen, the actual spectroscopic scanning, and the interpretation of the spectra. (TW)

Discusses the construction of artificial reefs for such uses as commercial fishing and recreational boating. Describes a class project in which students construct a small artificial reef and observe the changes over time in terms of temperature, salinity, flora and fauna. (TW)

Concept maps and structured/clinical interviews were completed by 25 fourth graders and 25 college freshmen to determine knowledge of the human circulatory system. Students (N=945) at various levels were then measured for misconception frequencies. Student preconceptions appear to be tenacious, but confrontation strategies may assist fundamental…

Develops and explains a format for a workshop which focuses on soap films and bubbles. The plan consists of: a discussion to uncover what children know about bubbles; explanations of the demonstration equipment; the presentation itself; the assembly of the workshop kit; and time to play with the bubbles. (ML)

Summarizes current state of knowledge about the impact of computer-based education (CBE) including meta-analysis of elementary, secondary, and postsecondary data. Topics include achievement, aptitude, attitude, retention, and time. Outlines directions for future CBE research. (JM)

Presents a model, organizational procedures and evaluative findings of a science curriculum development program. Inservice teachers co-operatively developed modular science courses for underachievers, lists of science skills and attitudes, and materials for environmental science, physical science and biological science courses. (ML)

Investigated if relationships existed between middle school students (N=105) science concept structure interrelatedness competence and their time on task, science achievement, scholastic aptitude, previous experience with concept structure interrelatedness, attitudes toward science, interest in science, science curiosity, and self-concept of…