Industry Terms and Definitions
An Internet Industry Initiative*

WEB MEASUREMENT STANDARD DEFINITIONS
As at 30th July, 2001 

Following is a set of web measurement standard definitions ratified for comment by the Internet Industry Initiative Steering Committee on Monday 30th July, 2001. These standard definitions will make it easier for advertisers and publishers to have greater confidence in site and user information. This will enable them to make more informed choices. 

Guidelines are currently in development and will be released in due course. These definitions are intended to be read in conjunction with the proposed guidelines for interpretation and implementation. 


*The Internet Industry Initiative is a joint initiative of: 
Australian Association of National Advertisers 
Audit Bureau of Circulations 
Circulations Audit Board 
Internet Industry Association 
Advertising Federation of Australia 
The Media Federation 
Australian Direct Marketing Association. 

Industry participants include: 
ABC Online, AC Nielsen, AC Nielsen eRatings.com, BMC Media, Carat Interactive, Emitch, Engage Australia, Euro RSCG, Excite, F2, Jupiter Media Metrix, Looksmart, NETX, News Interactive, Ninemsn, OzEmail Internet, Red Sheriff, Roy Morgan Research, Sinewave Interactive (Hitwise), Telstra, Tempest Online Media and Yahoo! 


STANDARD DEFINITIONS

PAGE REQUEST	A file or a combination of files sent to a USER as a result of that USER's request being received by the server
PAGE DOWNLOAD	A file or a combination of files received by a USER as a result of that USER's request being received by the server
UNIQUE HOST	An individual IP address
SITE SESSION	A series of PAGE REQUESTS OR PAGE DOWNLOADS served in an unbroken sequence from within the site to the same USER
VISIT	A series of one or more PAGE REQUESTS OR PAGE DOWNLOADS, served to one USER, which ends when there is a gap of 30 minutes or more between successive PAGE REQUESTS OR PAGE DOWNLOADS for that USER
INTERNET SESSION	An unbroken period of time during which a user is connected to, and active on, the internet
UNIQUE USERS	An aggregate of USERs over a time period, where multiple VISITs by the same USER are removed
INDIVIDUAL USER	A person who can be identified, across multiple access points, by a certifiable registration ID
UNIQUE AUDIENCE	A projection based on an individual user and a clearly specified universe

Article courtesy of the Internet Industry Association.