Component-based usability testing: Difference between revisions

Revision as of 19:21, 25 October 2010

Revision as of 19:23, 25 October 2010

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Component-Based Usability Testing (CBUT) is a testing approach which aims at empirically testing the usability of an interaction component. The latter is defined as an elementary unit of an interactive system, on which behaviour-based evaluation is possible. For this, a component needs to have an independent, and by the user perceivable and controllable state, such as a radio button, a slider or a whole word processor application. The CBUT approach can be regarded as part of [[component-based software engineering]] branch of [[software engineering]].

==Theory==

CBUT is based on both software architectural views such as MVC, PAC, ICON and CNUCE agent models that split up the software in parts, and cognitive psychology views where a person’s mental process is split up in smaller mental processes. Both software architecture and cognitive architecture use the principle of hierarchical layering, in which low level processes are more elementary and for humans often more physical in nature, such as the coordination movement of muscle groups. Processes that operate on higher level layers are more abstract and focus on a person’s main goal, such as writing an application letter to get a job. The Layered Protocol Theory (LPT), which is a special version of Perception[[Perceptual Control Theory]] (PCT), brings these views together by suggesting that users interact with a system across several layers by sending messages. Users interact with components on high layers by sending messages, such as pressing keys, to components operating on lower layers, which on their turn relay a series of these messages into a single high level message, such as ‘DELETE *.*’, to a component on a higher layer. Components operating on higher layers, communicate back to the user by sending messages to components operating on lower level layers. Whereas this layered-interaction model explains how the interaction is established, control loops explain the purpose of the interaction. LPT sees the purpose of the users’ behaviour as the users’ attempt to control their perception, in this case the state of the component they perceive. This means that users will only act if they perceive the component to be in an undesirable state. For example, if a person have an empty glass but want a full glass of water, he or she will act (e.g. walk to the tap, turning the tap on to fill the glass). The action of filling the glass will continue until the person perceives the glass as full. As interaction with components takes places on several layers, interacting with a single device can include several control loops. The amount of effort put into operating a control loop is seen as an indicator for the usability of an interaction component.

==Testing==