Experiment!: Planning, Implementing and Interpreting

5.3 Building Theories

Students in the physical sciences often think of theories as mathematical equations that sum up the essential characteristics of a certain class of phenomena. Are such laws the goal that we must aspire to if we want to contribute to theory? Molander [4] concisely defines theories as “systems of statements, some of which are regarded as laws, that describe and explain the phenomena within a certain area of investigation in an integrated and coherent way” (author's translation). By this definition the answer to our question is no, because statements are not necessarily made in the language of mathematics. It is, in fact, quite easy to find examples of important theories that are not mathematical, such as plate tectonics in geology or evolution in biology.

Theories make statements about what we are going to call theoretical concepts. These represent certain aspects of reality and are used to facilitate our thinking about the world. Theories can be seen as rules that apply to the concepts. Newton's third law, for example, states that “the forces of two bodies on each other are always equal and in opposite directions”. This is clearly a strict and general rule that applies to the concepts of forces and bodies. But we do not have to aspire to come up with something like Newton's laws to make valuable contributions to theory. We only have to contribute with good, general knowledge that in due course may be integrated into a greater, more general theory. The established ...