The Inquiry Project has been pursuing the idea that many of the difficulties students later have with the atomic molecular theory stem from limitations in their macroscopic understandings of matter. We are interested in deep and broad change in concepts which consist of (i) invariants, that is, objects, properties, and relations (ii) associated situations and (iii) symbolic representations.

We investigate two broad advances in students’ thinking. The first concerns a shift from perception-centered to model-mediated thinking about matter; that is, from thinking about matter initially as fully and directly accessible through perception to, over time, a theoretical construct having certain properties that contribute to observable phenomena. Crucial to this shift is the recognition that materials can play roles in an object’s behavior. For example, a child might initially think simply that balls are inherently bouncy. Later, she will realize that a ball’s bounce depends on the materials of which it is made (e.g. rubber balls bounce differently from wooden balls).

A second focus has been on students’ quantitative reasoning, their ability to examine phenomena in terms of physical quantities and their relationships. Key here is the notion that quantities are continua consisting of measures that can be ordered (by weight, volume, brightness, distance, etc.), operated on (added, subtracted, multiplied, divided etc.). Furthermore relationships among quantities can be can be described through the language and tools of mathematics.