Choosing and Using the Best Metas

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Choosing and Using the Best Metas
Hyper-searching the Web

• Michael Hunter
• Reference Librarian
• Hobart and William Smith Colleges
• for Rochester Regional Library Council
• Member Libraries Staff
• Sponsored by the
• Rochester Regional Library Council
• Supported by Library Services and Technology Act
  (LSTA) and/or
• Regional Bibliographic Databases and Resources
  Sharing (RBDB) funds granted by the
• New York State Library 2002

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For Today

• Metas History and Functions
• Search and Retrieval Issues
• Major Players in 2003
• Clustering Technology
• More Good Metas
• Web Search Agents
• Evaluating Metasearch Services

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Metasearch defined . . .

• Group of search engines, subject directories
  and/or databases made searchable through a common
  interface.
• Results may or may not follow the original
  sources rankings
• Today our focus is free metaengines using
  subject directories (Yahoo, LII, OD) and
  crawler-based engines as sources (Google, FAST,
  Teoma)
• We will NOT examine specialized or Deep Web metas

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A GOOD Meta will . . .

• Re-format queries to be compatible with search
  syntax of each source
• Enable searchers to use advanced features (when
  the sources support them)
• Indicate overlapping results without repeating
  them
• Perform additional processing of results, eg.
  ranking for appropriateness, catagorization, etc.
  
• Use only sources with unique databases

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The beginnings of metasearch

• A conceptual descendant of Veronica
• March 1995 Harvest (later Savvysearch, now
  Search.com) developed at Colorado State by Daniel
  Dreilinger
• July 1995 Metacrawler developed at U. of
  Washington by Selberg and Etzioni
• Metacrawler Architecture for Resource
  Aggregation on the Web 1996

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The beginnings of metasearch

• 1996 - Dogpile
• 1998 - Ixquick
• 1999 - Kartoo
• 2000 - Ithaki
• 2001 - Vivisimo

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More facts about metas

• Flavor determined by choice of sources
• Comprehensive
• Vivisimo, Ixquick, Metacrawler
• General Lifestyle, popular culture
• Dogpile, Profusion
• Commercial
• Search.com, Excite_at_home

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Metas and retrieval

• Metas search quickly but not deeply
• Search time or a quantity of searches are
  purchased from sources (typically top 10-50 hits
  from each)
• Metas are subject to time-out limits from their
  sources
• Each source is usually NOT searched for each
  query

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Metas and retrieval

• Dumbing Down the Query
• Advanced features are often not available, and
  then only those that are shared among sources
• Default setting for time-out is the shortest set
  to maximum for more comprehensive searches (when
  available)
• For most metas, advertising is the only source of
  revenue software sales are rare

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Metas and retrieval

• What is their place in my search strategy?
• Metas best used for simple searches, with little
  (or no) syntactic complexity
• Use them to find the top few sites on a topic
• For a quick overview of a topics coverage on the
  Web in general
• Use them as a last resort for highly focused
  topics that elude your usual search tools
• As a possible indication of coverage of a topic
  among several engines (NOTE problematic)

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Searching the metas

• Results depend on
• Choice of sources
• Query processing speed OF THE SOURCE
• Length of time spent at each source

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A search comparison . . .

• Searched heterotropia (abnormal binocular vision)
  on 4/21/03
• Vivisimo 77 Shortest 126 Longest
• Ixquick 37 from at least 450 results
• Profusion 30 Shortest 39 Longest
• Metacrawler 42 Shortest 61 Longest
• Webcrawler 31 Shortest 80 Longest
• Dogpile 29 (no time-out option)
• Excite 41 Shortest 31 Longest

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Stability of ResultsSearched kids of survival
(modern art group) as a phrase at 3-minute
intervals (time-outs at default setting)
4/21/03
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Metas and ranking options

• Listing by SOURCE
• Usually retains ranking of source
• COMBINED Listing options
• Indicate source of each result
• Indicate duplicates without repeating them
• Indicate position in original sources ranking
• Most duplicated hits listed first
• Disclose paid listings (if disclosed by source)

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Vivisimo

• http//vivisimo.com
• Sources Altavista, Yahoo, MSN, Netscape, Lycos,
  LookSmart, Gigablast, Vizzavi, BBC, Librarians
  Index to the Internet plus 11 specialized news
  sources and 7 specialized business, medical and
  governmental sources
• Offers full Boolean and phrase search (if
  supported by the source)

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Vivisimo

• Offers the following customizations
• Selection of sources searched
• Total number of results retrieved
• Length of search (time-out period)
• Results combined
• Source for each result given
• Ranking data from that source given
• Duplicates noted, but not repeated

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Vivisimo

• Other features
• Results are clustered by keyword prevalence or
  website of origin
• Offers a preview of each result in a separate
  window
• Offers vertical searches Top News, Business
  News, Tech News, Sports News

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Clustering results (folders)

• Automated subject analysis
• Facilitates navigation and query refinement
• Can be hierarchical (folders within folders)
• One document may appear in several folders
• Northern Light first public search engine to make
  use of folders

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Clustering technology in a metasearch environment

• Real-time processing of results retrieved from
  sources
• Variety of data can be returned from each source
• Url
• Title
• First few sentences
• Human-created summary
• Folder creation varies according to data from
  sources and processing time available at the
  moment of the query

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Clustering -- Step 1

• Significant terms are identified from all results
  based on
• Frequency of term(s)
• Position of term(s)
• Normalization algorithms applied
• Documents analyzed for word variants (stemming)
• Norms set (authority control)
• game downloads download games
• downloading games
• Folder labels created

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Clustering Step 2

• Each result from the sources is matched against
  the set of folder labels and assigned to one or
  more folders
• By linguistic analysis (term position, predictive
  descriptive importance)
• By statistical analysis (term frequency)
• Final, proprietary analysis combines these (and
  more)
• Remember The full documents are not available
  to a meta for this type of processing

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Profusion

• http//profusion.com
• Sources Altavista, Yahoo, MSN, About.com, Adobe
  PDF, AOL, LookSmart, Lycos, Netscape, Raging
  Search, Teoma, WiseNut
• Offers full Boolean and phrase search (if
  supported by the source)

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Profusion

• Offers the following customizations
• Selection of sources searched
• Total number of results retrieved
• Length of search (time-out period)
• Offers option of results listed by source or
  combined listing
• Source for each result given
• Ranking data from that source given
• Duplicates noted, but not repeated

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Profusion

• Other features
• Results can be sorted by relevance score, title
  or URL
• Similar Result enhancement
• Profusion Relevance Score shown
• Search terms highlighted in results listing
• Set Search Alert feature stores searches and
  alerts user to page changes requires setting up
  a (free) account
• Search Analysis available
• Offer vertical searches Deep Web content in 21
  broad categories News

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Ixquick

• http//ixquick.com
• Sources Altavista, Netscape, Gigablast, Adobe
  PDF, Avaya PDF, AskJeeves, Teoma, Go, Open
  Directory, Overture, Kanoodle, LookSmart,
  WiseNut, FindWhat, Yahoo, MSN
• Offers full Boolean and phrase search (if
  supported by the source)
• Offers the following customizations
• Selection of sources searched
• Length of search (time-out period)

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Ixquick

• Results combined
• Source for each result given
• Ranking data from that source given
• Duplicates noted, but not repeated

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Ixquick

• Other features
• Offers 7 field searches (when supported by
  sources)
• Clusters hits from same site
• Highlights search terms in each hit
• Offers Related Searches
• Offers vertical searches MP3, News, Pictures

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iBoogie

• http//iboogie.com
• Sources Altavista, Yahoo, MSN, FAST, FindWhat,
  Teoma, WiseNut, OpenFind
• Boolean and phrase search somewhat unreliable
• Offers the following customizations
• Selection of sources searched
• Total number of results retrieved
• Length of search (time-out period)

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iBoogie

• Results combined
• Source for each result given
• Duplicates noted, but not repeated
• Other features
• Adult content filter (when supported by source)
• Language limit (when supported by source)
• Clusters results by keyword and/or website
• Offers Similar Pages enhancement
• Offers vertical searches Newspapers,
  Bookstores, Reference, Shopping

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Metacrawler

• http//metacrawler.com
• Sources FAST, Google, About.com, AskJeeves,
  FindWhat, LookSmart, Inktomi (?), Open Directory,
  Overture, Search Hippo, Sprinks, Teoma
• Offers Boolean and, or (no not) and phrase
  search (if supported by the source)
• Offers the following customizations
• Selection of sources searched
• Total number of results retrieved
• Length of search (time-out period)

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Metacrawler

• Offers option of results listed by source or
  combined listing
• Source for each result given
• Duplicates noted, but not repeated
• Other features
• Offers Related Searches
• More like this results enhancement
• Offers a wide range of vertical searches Images,
  MP3, Shopping, Subject Directory, Multimedia,
  News, Message Boards

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Dogpile

• http//dogpile.com
• Sources Google, Fast, About.com, Ah-ha,
  AskJeeves, FindWhat, LookSmart, Open Directory,
  Search Hippo, Sprinks, Overture, Inktomi (?)
• Offers Boolean and, or (no not) and phrase
  search (if supported by the source)
• Offers the following customization
• Selection of sources searched

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Dogpile

• Results listed ONLY by source
• Source for each result given
• Other features
• Offers Related Searches
• Offers a wide range of vertical searches, similar
  to Metacrawler Images, MP3, Shopping, Subject
  Directory, Multimedia, News, Message Boards

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Web Search Agentsaka desktop client search
programs

• Software must be purchased
• Queries a fixed set of engines, directories,
  news and other databases
• Sites that review and feature search agents
• Searchenginewatch.com
• Searchengineshowdown.com
• www.botspot.com
• www.agentland.com

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Web Search Agentstypical features

• Queries are re-formulated to follow syntax of
  source databases
• Duplicates removed
• Additional ranking performed
• Source given
• Optional sort orders
• Optional grouping of results into folders
• Many output options (html, word processor, xml,
  e-mail and more)

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Web Search Agentsdifferent from other metas?

• Differences from the (good) free metas
• Many more sources queried
• Several output options
• Update option (re-running the search at specified
  intervals)
• Customizable search parameters

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Web Search Agents

• BullsEye Pro 3.0 199
• BullsEye Plus 49.99
• Covers 1000 sources
• Removes dead links
• Multiple language capability
• Government and News search groups
• Customization of sources available for an
  additional fee
• All other typical features
• Available at intelliseek.com

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Web Search Agents

• Copernic Pro 5.02 79.95
• Copernic 2001 Plus 39.95
• Copernic Plus Basic Free
• Pro version covers 1000 sources
• Removes dead links
• Post-search refinement and processing of
  retrieved results
• Automatic document summarizations (requires more
  software)
• All other typical features
• Available at www.copernic.com

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Ultrabar choosing your own sources

• Free download
• Searches a small set of pre-selected engines and
  allows more to be added, including Deep Web
  resources
• Offers search term highlighting
• Does not re-formulate queries for each source
• No output options
• Available at ultrabar.com

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Evaluating metasearch services

• What are the sources for the results?
• Good general search engines and high-quality
  directories? Shopping engines? Do any sources
  share the same database?
• What search features are offered?
• Remember, these are only in effect for the
  sources that support them.
• What results-based enhancements are offered?
• Clustering? More like this? Highlighting of
  search terms? Related Searches?

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Evaluating metasearch services

• What factors determine the ranking of results?
• Is there any processing of results after
  retrieval from the sources?
• Is the source and/or ranking in that source given
  for each hit?
• Can the user expand the number of sources
  searched and/or the search time?

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Evaluating metasearch services

• Use your own test-drive questions and compare
  with results from other meta-engines and good
  single engines and directories.
• Search for questions in specialized subject areas
  you are familiar with (tests database depth).
• Search for very recent topics (tests database
  freshness)

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Evaluating metasearch services

• Check its popularity through an independent
  rating or popularity monitoring service
• Media Metrix http//www.mediametrix.com/
• The oldest user-based rating service on the Web
  lists top 50 most visited sites.
• PC Data Online http//www.pcdataonline.com/reports
  /
• Check for information at the site
• About, FAQ, Contact Us

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A GOOD meta will . . .

• Re-format queries to be compatible with search
  syntax of each source
• Enable searchers to use advanced features (when
  the sources support them)
• Indicate overlapping results without repeating
  them
• Perform additional processing of results, eg.
  ranking for appropriateness, catagorization, etc.
  
• Use only sources with unique databases

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In conclusion . . .

• How do metas fit into my search strategy?
• Metas best used for simple searches, with little
  (or no) syntactic complexity
• Use them to find the top few sites on a topic
• For a quick overview of a topics coverage on the
  Web in general
• Use them as a last resort for highly focused
  topics that elude your usual search tools
• As a possible indication of coverage of a topic
  among several engines (NOTE problematic)
• Other uses??

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Thank you and Best of Luck with Metaengines!

• Michael Hunter
• Warren Hunting Smith Library
• Hobart and William Smith Colleges
• Geneva, NY 14507
• [phone]
• hunter_at_hws.edu