Matrix, Search Engines: Deja News

Deja News Research Service

Key Links

• Quick Search: http://www.dejanews.com/
• Power Search: http://www.dejanews.com/forms/dnq.html
• Query Filter: http://www.dejanews.com/forms/dnsetfilter.html

Organization

• Deja News is an exclusively searchable index of articles and information posted to the Usenet since March, 1995.
• The search software is a custom software solution which accepts multiple keywords, phrases, Complex Boolean, Proximity, and Wildcard searches in any combination. Context operators control where in the article to search for keyword matches: author, newsgroup, subject, or date.
• The Power Search interface gives the user control over search parameters such as database (1-3 months or since March 1995), length and format of the results page, how the results are sorted, and whether to search for recent or older articles.
• Users can construct a Query Filter, which restricts which newsgroups, dates, and authors will be returned on subsequent searches.
• The database is surprisingly complete, containing articles from most Usenet newsgroups, about 11,500 in all, excluding only certain groups from the alt, soc, and talk hierarchies. The database ranges back over a year, and they are currently extending their coverage backwards and over many of the previously excluded groups.
• An author can prevent the indexing of a posted article by including the following text in the article's header: X-No-Archive: Yes.
• Indexed information is not restricted by content, except within the parameters established above.

Administration

• Gathering is performed automatically one or two times a day. Articles posted to included Usenet newsgroups are automatically downloaded and indexed with no work by the author.
• Most queries complete in 5-10 seconds.
• The index contains articles from about 11,500 newsgroups, ranging back March 1995, and is updated frequently. Since the service returns the matching articles, there are no such things as dead links.
• Each of the search pages is very simple and easy to use, with abundant links to relevant help and tutorials. The graphics are small enough to be useful without choking modem bandwidth.
• The help pages and search tutorials are a great way to learn just what the search engine can do.