Complete dissemination is unnecessary.
The required dissemination level depends upon how documents are allocated among sites. Low dissemination is needed for random document allocation, but higher levels are needed when documents are allocated based on content. We define parameters to control dissemination and document allocation and present results from four test collections. Permission to make digital or hard copies is granted provided that copies are not made or distributed for profit or direct commercial advantage, and that copies show this notice on the first page or initial screen of a display along with the full citation. Server Ranking for Distributed Text Retrieval Systems on the Internet.