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…

The constructivist hypothesis that the acquisition of domain-specific conceptual knowledge (declarative) requires the use of general procedural knowledge was tested. Students (n=314) were classified as reflective, transitional, or intuitive thinkers and presented with four concept-acquisition tasks. Skill in hypothetico-deductive reasoning…

Examines 11 elementary science texts in terms of conceptual structure and reasoning demands using concept maps. Reports that (1) the conceptual structures vary widely across texts; (2) most of the structures are well defined; and (3) the reasoning demands are above the developmental capabilities of most of primary-level children. (Author/YP)