Explanatory standards in biology and physics textbooks: The case of polymers

Learning to construct good scientific explanations is an important aspect of learning science. To this end it is important to also consider that the detailed standards for good explanations differ across the sciences. Practitioners face these differences, for instance, when interdisciplinary work is attempted. This paper reports on a comparative qualitative study of exemplar explanations on polymers from molecular biology and polymer physics aiming to map the differences in standards for good explanations between the two domains. The study gives detail to the theoretical expectation that mechanistic explanations are the ideal in molecular biology whereas derivations play the central role in polymer physics. Mechanistic explanations in molecular biology focus on material objects with a function-determining structure. In polymer physics derivations are the preferred kind of explanation. Derivations focus on variables, particularly, physical quantities like energy and entropy, whereas the three dimensional structure of polymers is often ignored. Differences in the kinds of explanations-seeking questions deemed relevant within the two domains are also identified.