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Asia-Pacific Forum on Science Learning and Teaching, Volume 11, Issue 1,
Foreword (Jun., 2010) John K. GILBERT The role of visual representations in the learning and teaching of science: An introduction
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Asia-Pacific Forum on Science Learning and Teaching, Volume 11, Issue 1,
Foreword (Jun., 2010) John K. GILBERT The role of visual representations in the learning and teaching of science: An introduction
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The scope of the visual mode of representation
Given the central role of sight per se in the repertoire of human senses, it is inevitable that a range of forms and sub-forms have come into existence.
Picture
The sub-forms constitute a continuum from the common meaning of ‘picture’ i.e that which is recorded by a camera (for example, of the equipment used in a laboratory distillation experiment), through the ‘simplified picture’ where parts of the original are removed for the benefit of emphasis (for example of distillation equipment with the clamps etc air-brushed out ), to the ‘sketch’, where only simplified depictions of all the core aspects remain (for example that of distillation as a general process). Cartoons may also be included in the picture genre.
All these sub-forms of ‘picture’ are two-dimensional analogies for three-dimensional objects, depicting not only the entities involved but also their spatial arrangement at any one moment. Animations, a variant of increasing importance in science education, enable changes over time to be represented (Milheim 1993). In summary, the codes of representation for pictures are concerned with the way that the third dimension is presented in two dimensions.
The picture sub-form is used badly in textbooks, very often treated as a decoration adding nothing to the written text, often used to echo textual statements, occasionally explaining ideas in a different way to that given in the text, and very occasionally adding something that cannot be expressed in writing (Pozzer and Roth 2003).
Diagram
The range of sub-forms of ‘diagram’ is extensive here, from the use of picture-like depictions of objects linked spatially or temporally or causally by arrows or lines, through to examples where the objects have been reduced to symbols and the links have become a grid. There seem to be no conventions on the use of diagrams in textbooks, so that a mixture is often used without justification for the decision that has been taken. This lack of protocol means that students are constantly inventing codes of representation before they can attempt to understand the message contained in a particular diagram. They may consequently acquire misconceptions when the personal code that they use is not that intended by the author of the representation.
Graphic sub-form
Because they enable large amounts of mathematical data to be presented in highly compact forms, there are a wide range of graphical sub-forms e.g. tables, pie charts, block graphs, line graphs, scatter plots. They all enable categorical, relational, spatial, temporal, causal , forms of visual data to be set out abstractly. The codes of representation between the sub-forms differ widely, such that they each have to be learnt separately. This task often falls to mathematics educators. In that case, alas, the transfer of such ideas into a science context is found difficult by many students (Roth, Bowen et al. 1999). Consequently, science teachers often teach the graphical forms themselves: this is effective when it does not conflict with what has been learnt by students in mathematics
Copyright (C) 2010 HKIEd APFSLT. Volume 11, Issue 1, Foreword (Jun., 2010). All Rights Reserved.
