APT: a description of user interface inconsistency

✍ Scribed by Phyllis Reisner

• Publisher: Elsevier Science
• Year: 1993
• Weight: 736 KB
• Volume: 39
• Category: Article
• ISSN: 0020-7373
• DOI: 10.1006/imms.1993.1060

✦ Synopsis

One of the basic tenets of interface design is that an interface should be "consistent". However, the meaning of the term remains elusive. Several attempts have been made to represent consistency (and inconsistency) formally. Although each formalism has built on its predecessors to increase our understanding, a crucial assumption is still missing. APT (Agent Partitioning Theory) is a formal description of inconsistency that includes the missing assumption. In addition to being a formal description, APT embodies assumptions about human cognitive behavior. The psychological correlates of APT involve notions of generalization and of inference which are frequently used in describing inconsistency. These psychological correlates are used to explain (1) which user errors will occur as a result of inconsistency, and why, and (2) why users are sometimes correct, sometimes not, in an inconsistent system.

Although some of the early formalisms state or imply that these formal descriptions can be used to identify inconsistency, they cannot do so. APT, and its predecessors, are not discovery procedures. They do not mechanically identify inconsistencies. They are tools to help an analyst do so.