Extends prior theory and research by postulating the existence of an intermediate class of concepts called 'hypothetical'. Investigates the hypothesis that three kinds of scientific concepts exist by constructing and administering a test on concepts introduced in a college biology course. Supports the hypothesis that intellectual development…

Explores the relationships between seventh-grade students' misconceptions of genetics and natural selection and four cognitive variables: reasoning ability; mental capacity; verbal intelligence; and cognitive style. Reports that only the reasoning ability was significantly related to the number of misconceptions. (Author/YP)

Assesses the role of science topic instruction combined with logical reasoning strategy instruction in teaching high school students about blood pressure problems. Reports positive effects of the combined instruction compared to science topic instruction. (Author/YP)

Compares the relative effects of hands-on and teacher demonstration laboratory methods on declarative knowledge and procedural knowledge achievement. Reports that students in the hands-on class were better on the procedural knowledge test than students in the demonstration class. (Author/YP)