Assessing Interactive System Effectiveness with Usability Heuristics and Markov Models of User Behavior

Abstract

The purpose of this research was to create a new measure of usability to aid in determining whether the intent of system designers is realized and to objectively assess user behavior as a basis for interface design recommendations. There are currently few quantitative, objective measures of usability among many subjective measures. A measure combining both objective and subjective data may be valuable in determining user perceptions of system designs and whether performance goals are achieved. The present research used a human computer interaction framework, representing the user, input, the system and output, as a basis for designer and user interface evaluation forms. These forms were used in combination with a Markov model of average number of user actions in task performance in order to determine an overall system usability effectiveness score. The methodology was applied to the evaluation of the design of a web-based ordering interface. The new measurement technique appeared to be sensitive to interface design changes and may be more effective than subjective methods (alone) for determining if interfaces meet design and performance objectives.