MODELING DISTANCE DECAY EFFECTS IN WEB SERVER INFORMATION FLOWS

Previous studies have shown that there is a direct correlation between the popularity of a medium and the cost in transmitting information t hrough that medium. On this basis the World Wide Web may become more i mportant as a mass medium than radio and television. Yet despite the e normous growth in Internet information and Internet-supported business es, there has been, as yet, little in the way of quantitative spatial analysis of information flows on the WWW. One major Issue is whether o r not distance influences the web sites that a user may visit. If dist ance is a factor, then the location of servers delivering content beco mes important. In this paper an analysis of information flows from U.K . academic web servers to the rest of the world is carried out. Using a UNIX utility cabled ping, the average time taken, for a defined amou nt of information to travel between the United Kingdom and sixty-six o ther countries across the Internet was measured. This time measurement known as latency is used as a measure of distance on the Internet. Th e latency measurements are combined with counts of visitors from each of these countries to approximately one hundred U.K. academic WWW serv ers and used to build a simple gravity model! of WWW information flows . The latency measurements between the United Kingdom and the other co untries were gathered over a week in 1996. The counts of visitors rela te to the total number of visits to the web servers over various times cales for the years 1995 and 1996. We make the assumption that the dis tance measurements used are relevant to the visit counts. We also assu me that all visitors from the .edu domain are geographically located i n the United States. The gravity model is used to determine the effect of Internet distance on the number of expected visits to a web server . The study shows that latency values are a useful metric for measurin g Internet distance. The results also demonstrate that the number of v isitors to a web site falls off with distance on the Internet, as meas ured by latency values.