IMGS Stats are now located at http://public.ornl.gov/hgmis/stats/stats_all.cfm?site=IMGS
Hits are all accesses for all files (text and graphics) on the website. Often used as a measure of a site's popularity but can be artificially inflated by large numbers of graphics and other 'tricks'. Page views are accesses for text files only; a better measure of the website than total hits. Visitor Sessions are the number of times visitors accessed the site. Unique Visitors are the number of visitors that accessed the site, counted by IP or domain name. Semi-accurate as one visitor can have several IP addresses and a single IP address can be used by many people (example: AOL has a limited number of IP addresses which serve a large number of people). Average Session Length measures the average amount of time a visitor spent on the site. Higher numbers indicate more extensive use of the site; 11 minutes is considered good.