The User Action Notation (UAN) is primarily a shorthand way to represent the steps (such as mouse button down) that a user would take to achieve a task result given a user interface design, existing or under development. In addition, the notation can be used to represent (1) feedback at the interface from the computer system to the user (such as highlighting an icon), (2) the resulting interface state (for instance, a file is selected) and, as appropriate, (3) the connection between the user action and the resulting internal state of the computer (for example, a file is marked for deletion).

This paper, one of a series produced by the Dialogue Management Project at Virginia Tech, introduces the notation through a carefully developed extended example. The research project seeks to create new user-centered interface representational techniques. These complement well-established computer science representational techniques and tools currently in common use for computer-centered construction of software.

The UAN offers a vocabulary of distinctions and mnemonic symbols that support task analysis. Though the paper concentrates on low-level physical user actions associated with devices, the examples show extensions to higher-level abstractions such as menus. The work is motivated by a literature review of current analysis and representational methods available to support design. An interesting discussion of time sequencing suggests how the notation can represent a range of synchronous and concurrent user tasks. The authors list eight commercial, government, and academic sites where people who are experimenting with UAN report that it is written and read with little training.

This interesting paper is a useful addition to the range of techniques (such as scenarios and walkthroughs) becoming available to support the design and development of usable interactive systems.