A Comparative Study of Quantitative Scales to Populate Affordance Structure Matrices

The Affordance Structure Matrix (ASM) is a concept exploration and attention directing tool to enable designers to take advantage of the special properties of affordances, such as form dependence and polarity of positive and negative affordances. However, in an ASM, as in other popular matrix based tools, the entities being mapped (in the case of an ASM, affordances and components, respectively) are typically assumed to be of equal importance. In this paper we present a comparative study of various quantitative scales used to populate ASMs. By using these scales, we can capture the relative importance of different affordances, for example that cutting the user is more important to avoid than annoying the user with noise. Also, by using scales of increased granularity for populating the interior of an ASM, the relative strength of relationships between product components and individual components can be captured. For example, larger, heavier components have a stronger relationship with transportability than smaller, lighter components. The results of the comparison studies on the case study of a shaving razor show that a scale of negative ten through positive ten for populating the interior of the matrix is necessary to produce results which clearly rank all of the components in terms of helpful and harmful relationships. The results also show that the scale used for populating the interior of the matrix has a much stronger effect on the results than does the scale used for weighting the individual affordances. An electro-mechanical razor is used as the consumer product in the comparative study. Based on the results of the study, practical suggestions for redesigning the razor are also suggested.