Summary12

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in a ubiquitous computing environment with multiple computers, most displays must be in the periphery by definition

activity theory provides a framework for describing context and thus for describing how peripheral displays should interact in various situations

4 particularly important parts of activity theory used in the study

1. activities, objects and motives - Activities correspond to long term (weeks, months, years) projects of a person or group of people. These projects are directed toward some object in the world like a new product design or a social relationship. An object may be physical or conceptual, but is always coupled with a motive - a driving force that seeks to satisfy some need or needs of the people in the activity

2. Actions and operations. In terms of how activities are executed, they are composed of goal-directed actions which are themselves composed of environmentally contingent operations. Actions are equivalent to the classic HCI notion of tasks, operations to the operations from GOMS.

3. Tool artifacts. In terms of elements in the world, activities are composed of an object, the person or people involved, and the tools that the people use to carry out and support the operations and actions in the activity. Tools are socially constructed artifacts that both encode the operations they are used in and guide the user in formulating goals and actions for using them.

4. Multiple, ongoing activities. People have multiple, ongoing activities at any given time; however they are generally working on only a subset of these activities through their current actions and operations.

the multiple ongoing activities

1. Dormant activities. This class includes activities that have been set aside by the user. Specifically, dormant activities are not serviced by any operation performed in the user’s current sequence of operations. Since these activities are dormant, they are not serviceable by any peripheral display and hence are irrelevant for design and evaluation.

2. Primary activities. This class includes activities that are serviced by the user’s primary action. In other words, it is the class of activities that are serviced by operations needed to complete the user’s primary action. We will refer to tools that support this class of activities as primary tools.

3. Secondary activities. This class includes the activities that are serviced by operations that are in the user’s primary action but do not promote the attainment of the primary action’s goal. In other words, these activities are not the focus of the user’s current action. Also, they are not likely to become primary in the near future.

4. Horizon activities. This final class of activities is similar to secondary activities with one important distinction. Both secondary and horizon activities are monitored by the user, but horizon activities are monitored with the intent that they will become the primary activity in the near future. In other words, a horizon activity was once a primary activity that is temporarily “on hold.” The user is monitoring some aspect of the activity to decide when to start working on it again.

activity theory definition of peripheral displays - any information display that 1. is a tool in at least one activity of its user 2. is used primarily at the operation level

evaluation metrics


- appeal(usefulness, aesthetics) - learnability - amount of time and effort required for users to learn to get info from display at operation level - awareness - amount of info shown by the display that users are able to recall, udnerstand or use -effects of breakdowns - how apparent breakdowns are to users and how easily can recover from them -distraction - amount of attention the display attracts away from primary action


high critical displays - displays that show critical things should present info in most readable form possible - metrics like appeal are less important then learnability, awareness breakdowns etc.

low critical displays - A non-critical activity display is a tool for maintaining awareness related to a relatively unimportant activity.

did 2 case studies