This paper describes an experimental study of three perceptual properties of motion: flicker, direction, and velocity. Our goal is to understand how to apply these properties to represent data in a visualization environment. Results from our experiments show that all three properties can encode multiple data values, but that minimum visual differences are needed to ensure rapid and accurate target detection: flicker must be coherent and must have a cycle length of 120 milliseconds or greater, direction must differ by at least 20/spl deg/, and velocity must differ by at least 0.43/spl deg/ of subtended visual angle. We conclude with an overview of how we are applying our results to real-world data, and then discuss future work we plan to pursue.