Abstract
The paper advocates the use of eye movement measurements in conducting empirical studies of software engineering tools, especially visualization techniques. Traditionally, measures such as accuracy and performance time have been used to assess and compare different tools for a given set of tasks. These measures are typically collected after the conclusion of an assigned task. Eye tracking adds a new additional dimension to the assessment arsenal by allowing access to the gaze activity of human subjects. The gaze activities can be captured quite precisely while a task is being performed. Thus, providing a unique opportunity to include measures of how exactly humans use a tool and ratiocinate their conclusions. A brief discussion on using the eye movements for assessing UML class diagram layouts is also presented.