Eye tracking is an important tool in usability testing of a screen-based user interface. Though eye tracking has been used in usability testing for quite a while, challenges remain. For example, how to accurately calibrate gaze point? How to interpret a scan pattern? This situation suggests a need for education of basic eye tracking knowledge and techniques in the usability community. In this tutorial, we will introduce the students to the basics of the human oculomotor system, the role of eye tracking in cognition, eye tracking recording techniques, and data analysis methods. Upon the completion of this tutorial, students will have a basic understanding of physiological and psychological mechanisms underlying eye tracking, data collection techniques, and data analysis methods.