Scientific thinking is both like and unlike the forms of thinking that individuals employ in their everyday lives. For example, in both science and everyday problem solving, people make inferences about the relationships between causes and effects by detecting and evaluating patterns of covariation between potential causes and outcomes (Kelley, 1973; Shultz, 1982). However, it is much less common for people to deliberately apply strategies and heuristics (such as the control-of-variables strategy) to definitively and systematically rule out factors that are not causal, although one does observe this form of thinking in certain specialized contexts, for example, those that call for accurate diagnosis (e.g., car repair, medicine). Moreover, causal relationships that go beyond simple, one cause/one effect can be very difficult for people to detect (Perkins and Grotzer, 2000). Similarly, people do not simply hold a catalog of unrelated beliefs; instead, they use their knowledge to make inferences that are internally consistent and that support explanations and predictions about novel cases (Gopnik and Meltzoff, 1997). Even third graders prefer explanations that are logically consistent (Samarapungavan, 1992). However, this does not necessarily mean that novices are explicitly aware of their beliefs and maintain or discard them by systematically appraising their adherence to the criteria that scientists deliberately apply when they evaluate alternative theories.
Because scientific and everyday thinking do not overlap perfectly, students sometimes find it confusing to grasp the rules of the game as they move between contexts. For example, it has been observed that when they are presumed to be designing and conducting experiments to learn about the causal structure of a complex system, children frequently are doing something else altogether—in some cases, trying to replicate outcomes that they consider interesting or favorable (Kuhn and Phelps, 1982; Tschirgi, 1980; Schauble, Klopfer, and Raghavan, 1991). Negotiating the sometimes subtle transitions between everyday thinking and the thinking valued in domains like science is a challenge for all students. Moreover, it may be particularly difficult for students who have had less experience with the forms of reasoning and talk that are privileged in American middle-class schools. Mainstream students (those who are white, middle- or upper-class, and native speakers of standard English) are more likely than culturally or linguistically diverse students to encounter ways of talking, thinking, and interacting in schools that are continuous with the practices (including knowledge, language, skills, and reasoning) and the expectations that they bring from home.