Search services: Alta Vista

Header

General information

• Type of service (according to TK's typology): Robot based index
• Access:(free, commercial) free
• Volume: 31 000 000 www pages from 476 000 servers and 4 000 000 Usenet articles from 14 000 news groups
• URLs known: 31 000 000
• Number of documents indexed: 31 000 000
• Publisher: Digital Equipment Corporation
• URL for Top-level Page: http://altavista.digital.com/
• Mirror sites: Yes (Northern Europe) http://altavista.telia.com/ and (Australia) http://www.altavista.yellowpages.com.au/
• URL for the organization: http://www.digital.com/
• History: "ALTA VISTA is the result of a research project started in the summer of 1995 at Digital's Research Laboratories in Palo Alto, California. By combining a fast Web crawler with scalable indexing software, the team was able to build a large index of the Web in the Fall of 1995. After two months of internal testing, we produced an even larger index consisting of the full text of over 16,000,000 pages. We made the site public on the 15th of December 1995. Within three weeks of launch, we were handling over two million HTTP requests per day. Nowadays Alta Vista is accessed 29 millon times per weekday."
• Update frequency of the whole database:continuous 4 000 000 pages/day
• Document rating, reviews, "added value" included: No
• Registration needed: No
• Costs: No
• Performance: Fast, good
• Response time: Fast
• Time outs: No
• Image download time: Fast

Harvesting

• Harvesting software: Scooter by Digital
• Robot (type; follows robot exclusion standard?): Yes
• Method:
• Human: No
• Automatic: Yes
• User registration: Yes
• User deletable: No
• Depth first:
• Breadth first: Yes
• Type coverage:
• WWW: Yes
• gopher:
• WAIS:
• ftp:
• telnet (OPACs):
• UseNet News: Yes
• Listserv:
• IRC:
• Other databases (numeric, commercial):
• Multimedia products (images, movie, sounds):
• Other types:
• Geographic coverage: World wide
• Subject coverage (General or specialized content): General
• Update frequency for visiting the same sites/documents again: 4-6 weeks
• Number of dead links:

Indexing

• Indexing software: Indexer by Digital
• What is indexed:
• Extracted information, fields indexed:
• Titles: Yes
• Headings: Yes
• Header information (included metainformation): META-tag
• File information (size, date): Yes, both
• Links (URLs): Yes
• The anchor text of links: Yes
• Other HTML tags: Applet, Host, Image, (Possible to constrain searches to the text, links and images excluded)
• Summary/excerpts (how generated):
• Full text: Yes
• What is not indexed:
• Separate metainformation provided by the search service: Possible to use META-tag to control what Alta Vista indexes from page. AltaVista will index the description and keywords up to a limit of 1,024 characters.
• Human cataloguing and indexing: No
• Human summary/abstract, excerpt, review: No

Retrieval system:

• Boolean (exact match): Yes (advanced query)
• Best match: Yes (simple query)
• Combination: Yes
• Vector retrieval:
• nonverbal (citation indexing):
• Other:

• Natural language:
• Word list (no Boolean operators associated): Yes (simple query)
• Boolean query: Yes (advanced query)
Boolean operators:
AND: Yes
OR: Yes
NOT: Yes
Nesting (parentheses supported): Yes (advanced query)
Restrictions:
mixing of operators: Possible
number of search keys: Not limited
• Proximity operators:
1. distance in number of words: NEAR (within 10 words)
2. distance in text structure: possible to limit the search to certain elements in the document (title, link, anchor, text, url, image, java applet)
3. bound phrases: Yes (by "word word")
• Other:
• Ranking algorithm: "A document has a higher score if the following hold: The query words or phrases are found in the first few words of the document (especially in the title of a Web page or in the headers of Usenet news articles). The query words or phrases are found close to one another in the document. The document contains more of the query words than some other document."
• ranking factors: User must specify search keys to be used when the relevance is counted (advanced query). In simple query relevance ranking is default.
• calculation of scores:
• User weighted words: User must specify relavance ranking criteria. Search keys and other keys can and should be used.(Advanced query)

 

 

Search terms:

• Truncation:
• Not supported:
• Automatic: No
1. stemming algorithm (morfological):
2. add wildcard (mechanical):
3. left (mechanical):
4. right (mechanical):
• Manual:
• left:
• right: Yes with asterisk (*) The *-notation will match from zero up to five additional letters in lower-case only. Capital letters and digits will not therefore be matched.
• internal: Yes (see above)
• What is the default and is it user changeable?: Truncation is not default, it is user changeable.
• String match features:
1. regular expressions:
2. internal masking: Yes (see above)
3. case sensitive specify: capital letters force to exact match
4. others:
• Any limits for a search term (character sets supported): Searches and displays Latin-1.
• Any limits for the size of a result set: No

• Possibility to specify source types: WWW or Usenet-news
• System searches as default:
• URL:
• Title, headings:
• Keywords:
• Summary:
• Fulltext: Yes
• cited URL, anchor text:
• others:
• User selectable search fields:
• URL: Yes
• Title, headings: Yes, title
• keywords:
• Summary:
• Fulltext: Default
• cited URL, anchor text: Yes both
• others: possible to search text-only (link-text excluded), image, host, java applet. In Usenet news articles it is possible to search from following fields: From, Subject, Newsgroups, Summary, Keywords
• Other search options:
• Stopword list:
• Uses the system a stopword list?: No
• How is the stopword list constructed?: (e.g. words exceeding a given absolut frequency are automatically put into the stopword list)
• Can the stopword list be sidestepped in a search?: (e.g. in a phrase search)

• Concept search: No
• Query expansion: Yes (Live Topics)
• Controlled Vocabulary, thesauri: No
• Relevance feedback, find similar: No
• Improve your search support or form: Previous search statemant is dispalayded in the result page. Possibly to modify search.
• Navigation and graphical features:
• Other features: Query presented in result page. Possible\ to enter new query or modify query in result page

• Result set information:
total: Yes (about)
subsets: Yes (only when search keys are enterd in result ranking criteria)
• Possible to choose number of displayed hits?: No
• Is the number of hits displayed limited by the service?: Yes (If result ranking is used AltaVista displays only first 200 hits.)
• What can be displayed:
• URL: Yes
• Hotlink to original document: Yes
• Title, headings: Title
• Keywords:
• Summary: Excerpt
• Fulltext:
• cited URL, anchor text:
• Show hits in context:
• Highlight hits:
• document size: Yes
• document last updated:
• document last visited: Yes
• Pre-defined display formats: standard, compact, detailed form or count only. Standard and detailed forms are the same.
• Other display options: No
• Information about relevance scores: "Documents with a high score will appear at the head of the list. High scores are assigned if the selected ranking word appears in the first few words of the document (say, in the title of a Web page or in a header), or if the document contains more than one instance of the ranking word."
Score displayed?: No
Matching terms: No
• Sorting:
URL-based:
others (size, number of links): Relevance based
• Afterprocessing of the result by the service:
duplicate check: Yes
link check: No
• Browsing structure (Subject catalogue), Organization of the result: No
• Browsing structure integrated with index?: No

User interface

• General description of interface:
• Clarity of interface:
• Clarity of search page or index:
• Text-Only support: Yes
• HTML Forms support: Yes
• URL for Forms Search Page: http://www.altavista.digital.com/cgi-bin/query?pg=q (simple query) ; http://www.altavista.digital.com/cgi-bin/query?pg=aq (advanced query)
• Query input form: The homepage of AltaVista is the same page as simple search interface.
• Optional forms for input:
• simple but limited: Yes (simple query)
• structured:
• free not limited: Yes (advanced query)
• other supported:

 

 
 
 

• Non-Forms support: No
• URL for Non-Forms Search Page:
• Adaptations to special browsers (Netscape, lynx):
• Online Help?:
• URL for FAQ Page: http://www.altavista.digital.com/cgi-bin/query?pg=h&what=web#FAQ
• URL for Help Page: http://www.altavista.digital.com/cgi-bin/query?pg=h&what=web
• Navigation Aids: Good
• Search Tutorials: Good
• Sample Searches: Yes
• Server Load Indicators: No
• What's New page: No
• What's Popular page: No

Documentation

• Manual:
• Literature: The AltaVista search revolution / Richard Seitzer, Deborah S. Ray, Eric J. Ray. - Berkeley : McGraw-Hill, cop. 1997. - ISBN: 0-07-882235-1
• Reviews:

Our evaluation of the service

Alta Vista seems to be powerfull search engine. Possibility to limit searches to certain fields is an advance same as boolean and proximity operators. Online manual is extensive. Query structures are not limited, but in certain situations I have doubted performance in complex search statements. Harvesting program Scooter doesn't seem to index sites very deeply. In sometimes AltaVista drops pages from it's index and after a while they reappear. You can get different results from simultanious, exactly same searches. Mirror sites databases are different from the main site.

 Last update: 97-04-04