TRANSFORMING VERBAL DESCRIPTIONS INTO MATHEMATICAL FORMULAS IN SPREADSHEET CALCULATION

A common subtask in spreadsheet calculation is the transformation of v erbal task instructions into spreadsheet formulas. This task can be us ed to study the relation of imagery to thinking. Research using physic s and mathematics problems has indicated that mental transformation fr om verbal to mathematical representations is not necessarily direct bu t is intermediated by imagery. Therefore, a human-computer interaction task such as spreadsheet calculation provides a good task environment for analysing mental imagery operations, the role of imagery operatio ns, and the role of intermediate imagery in thinking tasks. Testing th e use of imagery in spreadsheet calculations also improves our underst anding of representational systems used in this specific task and in u ser interfaces in general. Four experiments provided different types o f evidence for the intermediate imagery hypothesis, which means that s ubjects do not directly transform verbal instructions into spreadsheet formulas. They first try to code an overall image of the areas referr ed to by verbal instructions, segment it into suitable fields, and onl y thereafter do they write down the set of formulas which best extract the information demanded. Typically, the field borders, used in this segmentation are often imagined and are not presented at all in the or iginal verbal task instructions. Intermediate imagery is a relevant no tion in discussing the construction of user models because the most im portant current models, such as GOMS, assume only propositional repres entations. Also, the use of images should be taken into account in des igning spreadsheet packages by providing features which aid analog inf ormation processing.