Abstract
This paper describes an experiment conducted to compare three technologies in delivering a multi-step maintenance procedure to a factory worker. Optical see- through augmented reality, a web browser and a traditional paper-based manual used as control were the three technologies. Both augmented reality and the web browser expoited voice recognition and text to speech capability thus enabling a hands free user interface. The measure of the experiment was time to completion. An entrance and exit questionaire were given to subjects to obtain qualitative measurements. Thirty-six individuals participated in a randomized block experiment design with repeated measures.