A coding scheme for use in the design of electronic consumer products for older adults

As digital technologies become ubiquitous, people’s ability to live independently is increasingly dependent on their ability to interact with electronic consumer products. The research reported in this paper relates to the design of domestic information-processing appliances such as washing machines and microwave ovens. Evidence from the literature and primary research with users indicates increasing numbers of older adults with age–related cognitive and physical impairments find using domestic information-processing appliances difficult or impossible. The usability of controls and displays are important because the functional capabilities of domestic information-processing appliances often extend beyond the day-to-day requirements of typical users. This paper presents a coding scheme that is intended as a tool to support the analysis of user interfaces of domestic information-processing appliances with a view to identifying and prioritising design improvement opportunities. The coding scheme captures cognitive and physical characteristics of interactions between domestic information-processing appliances and users and provides a means of relating these interactions to the activity that the appliance is intended to support. Results from experiments with two older users, one using a microwave oven and the other a washing machine, carrying out specified tasks are reported in this paper. Initial observations indicate that participants tend to talk more when they encounter difficulties in completing the task. Application of the coding scheme showed cognitive processing time was spent evaluating and remembering, and operational procedure time was spent applying knowledge of the task to the programming of the interface. The study found that the use of symbols as visual instructions on the user interfaces was the most disabling because symbols that lacked meaning for the users caused the majority of impediments to workflow in the form of interaction breakdowns and focus-shifts.