The purpose of this special issue is to explore digital highdefinition television (HDTV) in all of its manifestations and to provide insight into its relationship to associated technologies. The historically significant convergence of entertainment (television and film), computing, and communications is embodied in digital HDTV. Relatively recent advances in digital communications, digital video compression and display technology have all contributed to the impending realization of a practical system by the HDTV Grand Alliance (GA). However, several contentious issues remain which, it is hoped, will not significantly delay the introduction of digital HDTV. Most of these issues arise from competing economic interests, each desiring to take advantage of economies of scale which result from accepted standards. In the case of the United States terrestrial broadcast HDTV standard, the use of public electromagnetic spectrum allows the U.S. Federal Communications Commission (FCC) to enforce the standard, thereby increasing the potential for widespread consumer use (see articles 1 and 5). The problem confronting the promoters and policy makers of HDTV is how to predict the effect of a given HDTV system