In this chapter the evaluation of human computer interaction (HCI) with mobile technologies is considered. The ISO 9241 notion of ‘context of use’ helps to define evaluation in terms of the ‘fitness-for-purpose’ of a given device to perform given tasks by given users in given environments. It is suggested that conventional notions of usability can be useful for considering some aspects of the design of displays and interaction devices, but that additional approaches are needed to fully understand the use of mobile technologies. These additional approaches involve dual-task studies in which the device is used whilst performing some other activity, and subjective evaluation on the impact of the technology on the person.
Key Terms in this Chapter
Context of Use: The combination of user, task, product, and environment during the achievement of a desired goal
Satisfaction: The subjective response of a user to interacting with a product
Referent Model: A product (or set of metrics) against which a given product can be compared
Efficiency: The optimal expenditure of resources by a given user in using a given product to achieve a desired goal in a given context of use
Usability: “… the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.” (ISO9241-11, 1998)
Dual-Task: The performance of two (or more) tasks at the same time. This could involve simultaneous performance or could involve some form of time-sharing between the tasks.
Effectiveness: The ability of a given user to employ a given product to achieve a desired goal in a given context of use