The Joint Roughness Coefficient (JCR) is probably the most commonly-used measure of roughness of rock joint surfaces in current use, and forms an important part of the Barton-Bandis rock joint shear strength criterion. The normal method of evaluating the JCR of a joint is by visual comparison of measured profiles against a set of standard JCR profiles produced by Barton and Choubey (1977). The aim of this study is purely to investigate the precision od the visual comparison technique in estimating the JCR value, using an Internet-based survey system. It does not attempt to evaluate the accuracy of this technique in comparison to others such as the tilt test, or those based on surface profile digitisation.