This mixed-methods investigation compared the relative impacts of instructional approach and context of nature of science instruction on preservice elementary teachers' understandings. The sample consisted of 75 preservice teachers enrolled in four sections of an elementary science methods course. Independent variables included instructional…

Reports research concerning the definition of variables by pupils ages 12 to 14 during investigative work. Findings suggest that an increase in the complexity of an investigation lowers the ability to identify relevant variables and substantive concepts intrude on the ability to define the appropriate dependent variable and to control variables.…

Part One of this paper summarizes six years of investigations devoted to the study of the influence that a variable called teacher "wait-time" has on development of language and logic in children taking part in elementary science programs. It discusses the relation of wait-time to 10 outcome variables. Wait time at two locations was studied in…