Separation thresholds for groups of 26 dyslexic and normal children attending the first year of secondary school were obtained with pairs of identically-oriented and spatially-overlapping straight lines presented at orientations varying from zero to 90 degrees. (Editor)

The effects of the outcomes "right" and "wrong" upon subsequent correct responding in paired-associate learning have recently been interpreted as a function of subject's memory of previous responses and their outcomes. Tests that interpretation in two experiments of recall procedures. (Editor/RK)

It is much easier to look for an unfamiliar character (such as an upside down A) embedded among familiar ones than to look for a familiar character (A) among unfamiliar ones. Furthermore, the nature of the background seems more important toperformance than the nature of the target. (Editor)

Presents the views of a prominent molecular biologist regarding recombinant DNA research. Contained are arguments for continuing research and a reassurance that the potential hazards from this type of research are overstressed. (CS)

Describes a DNA fingerprinting simulation that uses vegetable food coloring and plastic food containers instead of DNA and expensive gel electrophoresis chambers. Allows students to decipher unknown combinations of dyes in a method similar to that used to decipher samples of DNA in DNA fingerprint techniques. (JRH)

Describes the use of recently constructed stormwater detention ponds to conduct a set of field and laboratory exercises in an undergraduate limnology course. Provides a number of logistical advantages that can benefit those teaching aquatic sciences. (JRH)

Describes an exercise designed to be used in an Advanced Placement (AP) chemistry course to accompany the study of thermodynamics. Uses Differential Scanning Calorimetry in teaching the concepts of thermochemistry and thermodynamics. (JRH)

Presents an experiment that provides students with an opportunity to investigate folk medicine and herbal cures and their accompanying claims. Involves isolating some active compounds from plant materials and demonstrating their antibacterial activity. (JRH)

Discusses the goals of experiments which show examples of the use of solar energy on a scale suitable for a school laboratory. Highlights the history of discoveries and developments in photoelectricity. Presents investigations and experiments, that can be performed by students. (JRH)

Describes the design of a new laboratory course that calls for experiments to be grouped in clusters. Each cluster has a unifying theme which gives coherence to the experiments. Other important guidelines in design were the use of computers, introduction of microscale chemistry, and use of instrumentation. Cluster examples include Carbon Is Number…

Discusses the use of student-generated rubrics in science classes where students design their own laboratory activities to solve open-ended problems. Promotes careful consideration of what constitutes open-ended work. Presents certain rubrics and grading criteria. (JRH)

Describes an experiment that measures the diffusion of ions in the liquid phase and shows that the relative distances of diffusion are related qualitatively to the inverse of the mass of the solvated ion. Involves soluble salts on opposite sides of a Petri dish diffusing through a layer of water and meeting to form an insoluble salt. (JRH)

Describes an experiment that uses air to test Charles' law. Reinforces the student's intuitive feel for Charles' law with quantitative numbers they can see, introduces the idea of extrapolating experimental data to obtain a theoretical value, and gives a physical quantitative meaning to the concept of absolute zero. (JRH)

Presents an experiment that uses thin-layer chromatography to identify various aspirin-free Bayer products and to determine whether the products are in fact aspirin-free. (JRH)

Presents an experiment that demonstrates that common substances, whether or not the students think of them as medicines, drugs of abuse, or foods, have toxic effects on Daphnia. Combines an inexpensive hands-on experiment with extensive discussion to help the students think about chemical concentration, potency, and the difference between harmful…