In the course of its evolution so far, science has produced a wealth of scientific and historical models. If the curriculum is to be made more coherent, it is necessary to select the most significant of these models for the curriculum. How is this to be done? One approach is through the identification of ‘key explanatory stories’ – those themes in science that have made the greatest contribution to our understanding of the natural world so far (Millar & Osborne, 2000). Examples of these stories are those about: chemical reaction; chemical bonding; the motion of the Earth; the formation, structure, and evolution of the Earth, the Solar System, the Universe; the action of forces; the causes of motion; the causes and direction of change; radiation and its interaction with matter (Millar & Osborne, 2000, p. 16). Each of these explanatory stories is built around one or more scientific/historical models. If an ‘explanatory story’ structure is ever adopted or the science curriculum, then the identification of the curriculum models involved will be straightforward.
In the meantime, it is possible to reconceptualise existing curricula in terms of models. The science curriculum for pupils aged 5–16 years in the UK, originally laid down in 1988 (DfEE, 1999) on pragmatic grounds as a structure imposed on a collection of facts does, surprisingly enough, lent itself to an analysis in terms of models. The curriculum can be structured around curriculum models of ‘the particular nature of matter,’ ‘energy,’ ‘forces’ and ‘cells.’ This structure has been successfully implemented in schools in the south of England.
For progression in their learning, pupils must encounter explanations that give both increased insight into the nature of particular phenomena and which can be used in respect of a increased range of phenomena. What does this mean for the models concerned? One approach might be through a successive introduction of the models in an historical sequence. An example is the sequence of models of acidity/alkalinity: