An interactive interface evaluation approach
Robert Baggen* and Rainer Wieland+
*TÜV Informationstechnik GmbH, Essen
+ Bergische Universität -- Gesamthochschule Wuppertal, Projektgruppe MenBIT
The user interface evaluation approach presented in the following paper was inspired by the concept of ambulatory assessment proposed by Fahrenberg & Myrtek ( 1996). In their studies, subjects carried portable devices for continuous physiological recordings and recurring assessments of several subjective states in a natural setting. In software evaluation however, physiological recordings are seldom applicable since most indicators correlate only weakly with the details of a design. Here, the focus is not on the effect of working conditions on the user, but on the conditions themselves as imposed by the design of a user interface.
Another starting point for the development of the approach was the observation, that computers with graphical user interfaces control dialog windows, menus and direct manipulations etc. and so literally "know" something about the work that is done with them. Nevertheless, logfiles as classical method for interface evaluation are considered difficult to process and lack important information about the subjective side of interface usage.
In the WorkLAB approach, we thus combined logfile recording with the recurring assessment of subjective judgements on dialog quality to a method we called context-related inquiry (Figure 1). Whenever the logfile tool finds a dialog situation worth an assessment, the users are prompted to rate the dialog quality on some scales which were developed according to the interface standards DIN EN ISO 9241 Part 10 and 11. Besides the automated triggering of ratings, the users are encouraged to give dialog quality ratings in any moment they feel it is necessary.
The technical setup for the WorkLAB approach mainly consists of a normal computer workplace which is equipped with the logfile tool. The tool records the logfile and sends trigger signals to PROTEUS, a psychophysiological mea-