Noting that children and adults often hold misconceptions about topics in content area texts, particularly those in the area of science where counter-intuitive notions about how the real world works abound, a study examined the effect of activating students' background knowledge about motion theory prior to asking them to read a physics text. Subjects included a group of 38 students who demonstrated incorrect prior knowledge of motion theory in two pretests. Students were provided with two types of texts. The refutation text consisted of information regarding certain principles of motion, but it discussed those ideas as being in contrast with students' intuitive ideas. The nonrefutation version described Newtonian mechanics but did not discuss any of the ideas as being in contrast with commonly held misconceptions about motion theory. Posttest results revealed that the refutation text was more effective at getting students to change their prior misconceptions about the principles of motion. It did not make any difference if students were asked to activate their prior knowledge or not. In lieu of refutation text, it was recommended that teachers use an anticipation-reaction guide or George Posner's and others' four-step model of conceptual change instruction to dispel students' counter-intuitive notions. (HOD)