Investigates the effects of two context variables on the performance of seventh-grade students on a qualitative and numerical proportional reasoning test. Explores the nature of the relationships between rational number skills, qualitative reasoning about ratios, and numerical proportional reasoning. (Author/YP)

Assesses the ability of tenth grade students (n=364) to acquire meanings of graphs that are frequently used in their biology textbooks. Indicates that the main source of failure to process information equally well from tables and graphs was not a lack of basic analytical skills but rather a lack of understanding of the relationship between…

Attempts to show that not only can density be taught to lower ability pupils but that by doing so, there is the possibility of assisting pupils to develop their reasoning powers. Lists teaching activities that help in this process. (CW)

Describes a study which was designed to determine the effect of a 25-hour introductory qualitative analysis course on high school students' understanding of formal concepts related to electrolytes. Suggests that introductory concrete experiences better prepare students to deal with more formal abstract concepts. (TW)

The purpose of this study was to investigate the relationship between the achievement of some abstract concepts in "molecular genetics" and prior knowledge, formal reasoning ability, and sex. The major findings of the study were: (1) prior knowledge had a high significant correlation with the achievement of abstract concepts; (2) the…