The role of visual representations in the learning and teaching of science: An introduction

These tasks of representation and their use can best be addressed against the background of a model of what happens to all stimuli, whether encountered through formal teaching or in everyday life.

In his ‘Dual Coding Theory’ (see Figure 1), Paivio proposes that verbal stimuli – those which come in verbal form (as speech) – and non-verbal stimuli (the rest: received through touch, sight, sound, taste) – are processed in different ways by sensory systems that are in common to them both (Paivio 1986). The items of verbal information are stored separately as what he terms ‘logogens’ which are capable of cross-reference to form ‘associative structures’. For example, when a person is studying electricity, they encounter the words ‘voltage’, ‘current’, ‘resistance’, and form them (it is hoped) into a network of ideas on the common theme of ‘electricity’. The items of non-verbal information received are also stored separately, here called ‘imagens’, which are also capable of forming associative structures. For example, a person studying human anatomy will meet a range of diagrams in textbooks with varying degrees of abstraction of the circulatory system. These can be linked together to provide an enriched understanding of that system. Most importantly, the two types of associative structures are capable of ‘cross-linking’ to form ‘referential connections’. Thus, hearing about Mendeleef’s Periodic Table and seeing it as a chart will enable the two sources of understanding to reinforce each other. When called upon to do so, an individual will either produce a verbal or a non-verbal output based on the relevant associative structures, or will produce one or both of them based on the referential structures that have been developed. As the presentation of a comprehensive account of verbal stimuli, non-verbal stimuli, their associations and referential connections would be very lengthy, this introductory paper is only concerned with those non-verbal stimuli presented in visual form.