Usage centred research for everyday product design.

Prospective users of a new design in the area of everyday products offer innumerable opportunities for measurement and observation, in view of both the diversity in user populations and the freedom of where and how to use a product. In this paper, the relevance of human data is assessed for their impact in meeting functional imperatives in a design. On the basis of empirical studies, the significance of the observation/registration of user activities, including perceptual and cognitive activities, and the use of actions actually carried out is demonstrated. For everyday products, these activities are found to be only loosely related to human characteristics such as sensory capacities, body dimensions and exertable forces. Such characteristics seem to combine a limited relevance for usage centred design with relatively easy measurability. In contrast, observation of user activities may be evasive and is often laborious. User trialling is seen as an obvious way to enable designers to accommodate prospective user activities in everyday product design.