It is often claimed that “experience is the best teacher.” While this is arguably true in many contexts, what we learn from our experience varies considerably in terms of its generality and usefulness. With respect to science, everyday experiences often reinforce the very conceptions of phenomena that scientists have shown to be limited or false, and everyday modes of reasoning are often contrary to scientific reasoning.
Students bring conceptions of everyday phenomena to the classroom that are quite sensible, but scientifically limited or incorrect. For example, properties are generally believed to belong to objects rather than to emerge from interactions.5 Force, for instance, is seen as a property of bodies that are forceful rather than an interaction between bodies.6 As described in Chapter 10, students believe objects to “be” a certain color, and light can either allow us to see the color or not. The notion that white light is composed of a spectrum of colors and that the specific colors absorbed and reflected by a particular object give the object the appearance of a particular color is not at all apparent in everyday experience. Scientific tools (prisms) can break white light into colors. But without tools, students see only white light and objects that appear in different colors (rainbows are an exception, but for the untrained they are a magnificent mystery).
Students enter the study of science with a vast array of such preconceptions based on their everyday experiences. Teachers will need to engage those ideas if students are to understand science. The instructional challenge of working with students’ preconceptions varies because some conceptions are more firmly rooted than others. Magnusson and Palincsar (Chapter 10) note that some elementary students in their classrooms believe that shadows are “objects,” but this preconception is easily dispelled with fairly simple challenges. Other preconceptions, such as the idea that only shiny objects reflect light, require much more time and effort to help students change their ideas.
It is important to remember that most preconceptions are reasonable based on students’ everyday experiences. In the area of astronomy, for example, there is a widespread belief that the earth’s seasons are caused by the distance of the earth from the sun rather than by the angle of the earth’s axis with respect to the sun, and it is very difficult for students to change these preconceptions.7 Many experiences support the idea that distance from a heat source affects temperature. The closer we stand to radiators, stoves, fireplaces, and other heat sources, the greater is the heat.