action plan a sequence of actions selected to achieve a goal
activities the collective ventures that provide context and meaning for people’s interactions with computers and other tools
activity design the first phase of reasoning about a new software system, in which the problems and opportunities of current practice are transformed into new ways of behaving
affective computing the study and design of user interfaces that explicitly engage and respond to people’s emotions or affective experiences
affordance perceptual characteristics of an object that make it obvious what the object can do and how it can be manipulated
analytic method usability evaluation based on a careful analysis or theoretical modeling of user interface features, ...