Context of this study
In recent years, French lower, high schools and university programs have explicitly suggested adding problem solving to other teaching methods. Problem solving is promoted as contributing to the scientific training of pupils, by drawing on the variety of their knowledge. The successive reforms of science education curricula and associated teachers practices since 2005 prompt us to re-examine research results disseminated among French teachers (Boilevin & Dumas-Carré, 2001) and theoretical approach to understand students activities and help teachers to design teaching sequences on the basis of research results.
This led to the creation of a research project, bringing researchers from different disciplines and teachers, from secondary school to university, to collaborate. This collaborative project, initiated in 2016, aims to highlight how problem solving in physics at secondary school, high school and university contributes to the appropriation of concepts.
Introduction
This study focuses on an activity proposed to middle school students in a collective resolution of sound propagation problem, and considers the influence of fictional elements during the problem-solving process. This approach was chosen by the teacher to be closer to daily knowledge of students and to help them to solve the problem. The session begins with a short clip of Star Wars II (Lucas, 2002). The clip shows Obi-Wan, speaking with his droid, traveling through an asteroid field in his spaceship. The view changes and students become a spectator outside the ship. The ship performs flying feats to avoid hitting the asteroid with a high speed. There is no noise. The largest block then receives the "seismic charge" dropped by the spacecraft. The explosion produces an intense blue light. The sequence ends before the asteroid fragments. The movie clip is shown three times to the students. After which the teacher distributes a document composed of four parts: instructions, description of the macroscopic and microscopic properties of the states of matter, description of the ear as a signal receiver and an experimental activity in which to the students are invited to place the flame of a candle in front of the loudspeaker of a speaker playing music.
Theoretical frame
The story is conceived as a tool enabling the student to rethink his experience of the world, through an alternative temporal experience: fiction (Doležel, 1998; Ricoeur, 1990). We consider the concept of "world" as a space in which the teacher and students are invited to enter and that is operated with its own laws. We use Lewis's (Lewis, 1978) theory of possible worlds to explain how these worlds are constructed and function, and to compare the fictional world to real world. This enables us to question divergent interpretations or explanatory systems in real world and fictional world, as well as basic elements of these worlds (for instance, is space filled with air in Star Wars?).
We consider the activity of problem-solving as a research activity based on a set of scientific and non-scientific knowledge (Dumas-carré & Goffard, 1997). Modeling is defined as the search for relationships between objects, phenomena and concepts, laws that enable to explain interpret and predict these phenomena (Bécu-Robinault, 2004; Tiberghien, 1994). Modeling involves to distinguish and articulate two levels: the one of objects and events and the one of theories and models. The first consists of descriptions of material objects and perceptible events - scientific or from everyday life. Explanations and predictions come either from scientific theories and models, or naïve (daily-life) theories. This approach helps to understand how students use concepts and models to study a real or fictional situation.