A PC Based Model for Prediction of Visibility and Legibility for a Human Factors Engineer's Tool Box

Target detection and legibility prediction problems are generally considered complex as they require a good understanding of knowledge in photometry, geometry, human visual functions and visual performance measurement. Therefore, only simple geometric or photometric models are generally provided in human factors text books in the forms such as equations, graphs, or nomograms. This paper presents an easy to use but a more comprehensive model developed for a human factors engineering class to understand the variables, photometric measurements and use of human visual threshold data. The model can be easily down-loaded and exercised by a PC user to quickly estimate visibility and legibility in a number of situations. The model serves as a great tool to analyze a number of “what if” scenarios and learn the basics of human visual performance. The model will be an excellent candidate for including in a practicing human factors engineer's tool box.