Different types of physics statements: How and why to choose them?

Reims, Francia

Conferencia; GIREP-ICPE-MPTL 2010 International Conference; 2010

Groupe International de Recherche sur l'Enseignement de la Physique / International Commission on Physics Education

Comprehension implies the construction of different levels of mental representations. We propose a comprehension model for Physics that posits the existence of three levels of representation with different ontological elements and different levels of abstraction: A Situation Model (referential, non-abstract world representation of objects and events), a Conceptual-Physics Model (abstract, in terms of laws, principles and scientific concepts) and a Formalized-Physics Model (usually, in mathematical language). Expert physics knowledge implies the construction of these three mental representations and the two-way transition from one to another. Our aim is to study how efficient academic problems are in the classroom to create these expert skills in physics students. Most of these problems are word-problems, i.e. problems with a small story statement. Our hypothesis is that the particular statement characteristics of the problems affect the problem solving processes and therefore, the skills to be developed. A small sample of academic physics professors participated in an exploratory study on problem solving skills. Subjects were audio and video-taped during a problem-solving interview. Records were analyzed to study similarities and differences in the solving processes of different types of word-problems. We use a set of two pairs of problems in the study. In every pair, both problems involve the same physics subject-matter and the same suitable explicit/implicit physics model. In other words, one statement tells a story in terms of ordinary world terms (objects and facts) but the other statement tells the story in terms of physics concepts. A set of indicators were used to determine the number of actions and time spent in each stage of the problem-solving processes. The analysis of the interviews supports the hypothesis that differences in statements generate different solving processes. Differences appeared associated with Conceptual-physics modeling skills. This highlights some significant differences to be considered by teachers when selecting problems. We discuss criteria to guide the selection of one or another type of statement.