Context-based science curricula: Exploring the didactical friction between context and science content

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Context-based science curricula under construction since the 1970s appear to display some didactical frictions when analysed retrospectively from the point of view of a problem-posing approach to teaching-learning. The core of such an approach is that students are provided with a motive for extending their science knowledge, skills and attitudes in a certain direction and therefore continuously are aware of why they are learning what. In view of such an approach, the didactical frictions in context-based teaching-learning materials relate to a weak or lacking real motive for learning and a mismatch between the supposed motive and the science content to be learned. These didactical frictions might be solved by giving the concept of context the more strict meaning of an ‘authentic practice’ in which typical problems provide a relatively self-evident motive for starting to go through a characteristic procedure for solving these typical problems which requires an input of relevant science knowledge, skills and attitudes. This paper attempts to explore the didactical frictions in context-based curricula and to tentatively answer the question whether the idea of restraining contexts to authentic practices could be helpful in solving these. Background, aims and framework In context-based science curricula – such as ChemCom, PLON, Salter’s Science, Chemie im Kontext and Physik im Kontext – practical applications and/or socioscientific issues act as a starter for the teaching-learning of science in an attempt to bridge the gap between the often abstract and difficult science concepts and the world the students live in. It was and still is expected that relating science to everyday life would make science teaching more interesting for a larger proportion of the students, that they would be more motivated to learn about, and thus would reach a better understanding of, the subject knowledge involved – although some of the projects mentioned would be glad to reach the first point only. This implies that the science content presented is necessary, and thus its learning is meaningful, for solving a practical or theoretical problem set by the context. In our experience, however, this relation between context and science content is not quite as unproblematic as it seems. From the point of view of designing teaching-learning sequences the problem appears to be a twofold didactical friction between context and science content: is science content really necessary for solving the practical or theoretical problem set by the context, and, if so, which science content? This paper attempts to explore these didactical frictions by means of a representative example from the PLON curricula – the physics unit Traffic and Safety – and to tentatively answer the question whether the idea of restraining contexts to authentic practices – as done in a recently developed chemistry unit Water Quality – could be helpful in solving these. The theoretical framework underlying this exploration is the problem-posing approach to teaching specific science topics. A problem-posing approach In general, ‘traditional’ science curricula as well as most context-based curricula adopt a teaching-learning strategy of top-down transmission, without really taking into account what students already know, think and are interested in (Lijnse, 1995). Such teaching almost unavoidably results in a process of forced concept development, which may – at least partly – explain the often disappointing cognitive learning results in science education. This points at the necessity of an improved teaching-learning strategy that takes the students’ existing preknowledge and skills into account, and that provides them with a motive to extend these in a specific direction. This reflects the adoption of the perspective of educational constructivism (Ogborn, 1997), combined with the idea of a problem-posing approach with a core of developing content-related motives that drive the students’ learning process: a coherent sequence of teaching-learning activities designed on the basis of a profound knowledge of the students’ relevant pre-knowledge as being coherent and sensible (instead of being wrong) and using their knowledge productively (instead of immediately trying to change or replace it) in a social process of the teacher’s and students’ coming to understand each other (Klaassen, 1995; Klaassen & Lijnse, 1996). An essential element of such a teaching-learning process is to provide students with contentrelated motives for starting and continuing their learning process. The combination of the students’ existing motive for learning and pre-knowledge about a specific topic should be used to induce in them a need for extending their knowledge. In a problem-posing teachinglearning process we aim at bringing the students in such a position that preferably they themselves, guided by the design of the teaching-learning activities, come to formulate this need for extending their knowledge. In other words: preferably the students themselves should pose the problem to be further investigated. As a consequence, throughout the ensuing process of solving the posed problem there should be ample opportunity for the students to put forward their interpretations of what has been learned – interpretations to be taken seriously and used productively by the teacher to drive the teaching-learning process forward. This process is then not only guided by the designed teaching-learning activities (top-down), but also guided by the students’ own motives, knowledge and questions (bottom-up). These ideas about a problem-posing teaching-learning process were introduced and elaborated in a design research project for the topic of radioactivity (Klaassen, 1995), followed by comparable projects about the introduction of an initial particle model (Vollebregt, 1998) and decision making about the waste issue (Kortland, 2001). These studies started the research programme on ‘didactical structures’ for the teaching-learning of specific topics, and – based on those – more general ones at our institute (Lijnse & Klaassen, 2004). For the purpose of designing teaching-learning sequences these ideas have been worked out into a didactical structure of four subsequent phases with specific didactical functions that have to be fulfilled in such a way that they assure the necessary coherence in the activities of the students: • Phase 1: Orienting and evoking a global interest in and motive for a study of the topic at hand. • Phase 2: Narrowing down this global motive to a content-specific need for more knowledge. • Phase 3: Extending the students’ existing knowledge, in view of the global motive and the more specifically formulated knowledge need. • Phase 4: Applying this knowledge in situations the knowledge was extended for. To this phase structure other phases can be added, depending on more extended educational aims, e.g. in the area of skill development. The second phase represents one of the main features of a problem-posing approach. Such a phase appears not to be present in the teaching cycles as published in the literature (Abraham, 1998). Those cycles almost exclusively deal with cognitive learning, even though it is also often written that one should not forget about the importance of motivation. In our approach, however, both are taken together and integrated from the start.Â