Interestingly, there are also experiences in which we can manipulate the intensity of heat by changing the angle of a heat source—by pointing a hair dryer on one’s head at different angles, for example. But without the ability to carefully control distance from the head or the tools to measure small changes in temperature (and without some guidance that helps people think to do this experiment in the first place), the relationship between heat and angle with respect to the heat source can easily be missed.
Students bring ideas to the classroom not only about scientific phenomena, but also about what it means to “do science.” Research on student thinking about science reveals a progression of ideas about scientific knowledge and how it is justified.8 The developmental sequence is strikingly similar to that described in Chapter 2 regarding student reasoning about historical knowledge. Scientific knowledge is initially perceived as right or wrong. Later, discrepant ideas and evidence are characterized as “mere opinion,” and eventually as “informed” and supported with evidence.9 As in history, the sequence in science is more predictable than the timing. Indeed, many students may not complete the sequence without instructional support. In several studies, a large proportion of today’s high school students have been shown to be at the first stage (right or wrong) when thinking about various phenomena.10
Research has also explored students’ reasoning regarding scientific experimentation, modeling, the interpretation of data, and scientific argumentation. Examples of conceptions that pose challenges for understanding the scientific enterprise are summarized in Box 9-1. While research findings have been helpful in identifying problematic conceptions, less is known regarding the pace at which students are capable of moving along the developmental trajectory, or undergoing conceptual change, with effective instructional experiences. The chapters that follow provide many compelling examples demonstrating the kinds of changes in student thinking that carefully designed instructional experiences can support.
How People Learn emphasizes that instruction in any subject matter that does not explicitly address students’ everyday conceptions typically fails to help them refine or replace these conceptions with others that are scientifically more accurate. In fact, the pioneering research that signaled the tenacity of everyday experience and the challenge of conceptual change was done in the area of science, especially physics.11 One of the pioneers was