context to another. What this means for science teaching is that for students to be able to use what they learn, they must understand the major concepts, build a strong base of supporting factual information, and know how to apply their knowledge effectively (Bransford et al., 1999).

Knowing science, however, is not only knowing scientific concepts and information. The research on learning indicates that students need to develop abilities to inquire similar to those in the Standards (and discussed in Chapter 2). All students need to learn strategies for scientific thinking (Linn et al., 1989). They should be able to describe a problem in detail before attempting a solution, determine what relevant information should enter the analysis of a problem, and decide which procedures can be used to generate descriptions and analyses of the problem (Glaser, 1992). Through scientific inquiry, students can gain new data to change their ideas or deepen their understanding of important scientific principles. They also develop important abilities such as reasoning, careful observing, and logical analysis (Minstrell, 1989; Rosebery et al., 1992). Thus the research on expertise confirms the importance of helping students understand major scientific concepts and related factual information, and develop a variety of inquiry abilities.

Research Finding 2: Students build new knowledge and understanding on what they already know and believe. Students have conceptions about natural phenomena, and those conceptions influence their learning. When consistent with ideas accepted by the scientific community, this “prior” or “informal” knowledge forms a strong base on which to build deeper understandings. Many learners’ preconceptions, however, are inconsistent with accepted, extant science knowledge. These preconceptions are generally ideas that are reasonable and appropriate in a limited context, but students inappropriately apply them to situations where they do not work (Anderson and Smith, 1987; Driver et al., 1985; 1994). Students often hold tenaciously to these ideas, and their preconceptions can be resistant to change, particularly using conventional teaching strategies (Wandersee et al., 1994). For example, many students continue to believe that the earth is hotter in the summer because it is closer to the sun, even after being “taught” the correct reason. In Chapter 3, Mr. Gilbert uncovered and worked with his students’ preconceived ideas about the moon’s phases as did Mr. Hull with his students’ conceptions of forces on stationary objects. In Chapter 5, Lezlie comments about recognizing her own “misconcep-