A Comparison of Real and Virtual Worlds for Human Factors Experimentation Philip N. Day, Patrik O'Brian Holt and George T. Russell Image Systems Engineering Laboratory, Department of Computing and Electrical Engineering, Heriot-Watt University, Riccarton, Edinburgh. EH14 4AS <URL: http://www.cee.hw.ac.uk/isel/> Tel: 0131 451 3028 Fax: 0131 451 3027 e-mail: {ceepnd, ph, gtr}@cee.hw.ac.uk Abstract This paper considers the use of virtual reality (VR) as a general purpose experimental tool, particularly in the area of human factors experimentation. A comparison of VR and conventional experiments is given in the context of current studies of the cognitive effects of visual delays, and conclusions are drawn. The main findings of this paper are that using VR as an experimental tool allows automation of data capture and yields large amounts of statistically clean data. In addition VR allows the experimenter to refine and extend experimental environments as required, although this does require a large initial investment of resources. Keywords: human factors, delayed visual feedback, virtual reality, working memory, experimental tools, visual interference