Searching the World Wide Web

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Searching the World Wide Web
Chapter 7-3
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Our Goals

• Directories, portals, and search engines
• How do the engines work?
• Getting the most from your searches
• Invisible Web
• Authoritative Information

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Three Methods of Searching

• Directories
• Portal
• Search Engine

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Directories

• Directories are organized indexes that allow you
  to browse through lists of Web sites by subject
  or topic.
• Directories are created by people.

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Directories

• Excellent for browsing
• Like visiting a library
• Clearly defined subjects

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Who Creates Directories?

• Libraries
• Nonprofit organizations
• Universities
• Dot-Com businesses
• but they are probably portals too

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A Sampling of Directories

• Librarians Index to the Internet www.lii.org/
• Open Directory Project www.dmoz.org
• Looksmart www.looksmart.com
• Yahoo www.yahoo.com

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Portals

• Portals offer a one-stop shopping look.
• Portals include e-mail, chat, auctions, news,
  weather, horoscopes, stock info, and more.
• Portals want to be YOUR starting point.

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A Sampling of Popular Portals

• Yahoo! www.yahoo.com
• Portals to the World from the Library of
  Congress www.loc.gov/rr/international/portals.htm
  l
• AltaVista www.altavista.com

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Search Engines

• Crawler-based Search Engines
• Spiders aka Crawlers visit websites and some
  of their pages periodically, and adds to index
• Scans links and adds them to their index
• Returns the information to the index or catalog
• Search engine software sifts the index and ranks
  in relevant order
• Some are Focused Crawlers

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Search Engine Watch http//searchenginewatch.com
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Other Search Engine Types

• News Search Engines
• Multimedia Search Engines
• Metacrawlers
• Kids Search Engines
• Regional Search Engines
• See http//searchenginewatch.com/links/

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Power Searching

• Command charts for major search engines at
  http//searchenginewatch.com/facts/ataglance.html
  
• Use Advanced Search at the search engine home
  page to zero in on relevant sites

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www.google.com
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www.google.com
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Understand Limitations of Search Engines

• Search spiders or crawlers do not crawl in
  real time
• Lag times getting info to the index vary by
  search engine
• If a website is not submitted to the search
  engine it wont be crawled
• Not every page from a website is crawled
• A webmaster can choose to not have a page crawled
• Formats like PDF, Flash, Zip files, executable
  programs, and others cannot be searched
• The Invisible Web

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Start Your Search Engines Here

• Google www.google.com
• AllTheWeb www.alltheweb.com
• Yahoo www.yahoo.com
• MSN http//search.msn.com
• Why? See http//searchenginewatch.com/links/majo
  r.html

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Other Resources for Search Engine Info

• Search Engine Showdown Search Engine Features
  http//www.notess.com/search/features/byfeature.sh
  tml
• Search Engine Watch Search Engine Features for
  Searchers http//www.searchenginewatch.com/facts/a
  taglance.html
• How to Choose a Search Engine or Directory
  http//library.albany.edu/internet.choose.html

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Directories Vs Search Engines

• When should you use a directory?
• When you have a broad topic
• When you want experts to recommend sites
• When you want to avoid irrelevant sites
• Examples topics
• Disabilities
• Civil War
• Welfare

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Directories Vs Search Engines

• When should you use a search engine?
• When you have a narrow topic
• When you are looking for a specific website
• When you want to search for a file type or
  language
• Examples
• Americans with Disabilities Act
• Battle of Gettysburg
• Welfare to Work

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The Invisible Web 4 Types

• Opaque search engines choose not to index
• The Private Web password protected
• The Proprietary Web registration required
  (either fee or free)
• The Truly Invisible Web cant search certain
  file formats and databases

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Examples of Invisible Web Sites

• Dictionaries http//www.m-w.com
• Telephone Numbers http//www.infospace.com
• Clinical Trials http//www.clinicaltrials.gov
• Library Catalogs http//www.libdex.com/webcats
• Philanthropy and Grant Information
  http//lnp.fdncenter.org/finder
• Translation Tools http//world.altavista.com

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More Information on the Invisible Web

• The Invisible Web Uncovering Information Sources
  Search Engines Cant See, by Chris Sherman and
  Gary Price, ZA 4550 .S54 2001
• http//www.invisible-web.net/ website that goes
  with the book. Includes a subject directory of
  invisible web sites.

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Evaluating Online Information

• Always judge a web page for relevance and
  accuracy
• Who is the Author?
• What is the Purpose of the site?
• Is the information Fact, Opinion, or Propaganda?
• Is the information Reliable and Credible?
• Is the information Current?

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Evaluating Web Sites Continued

• Can you find this news reported on a legitimate
  news website?
• Who is the sponsor of the website?
• Are there inconsistencies or inaccuracies in the
  information?
• If an organization is mentioned by name, does the
  organization have any related information on this
  website?

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Thank You.!!! ?

• You can find this PowerPoint presentation on the
  Arlington Campus Library Website at
  http//library.gmu.edu/libinfo/acl.html under
  Useful Sites - bottom right of screen.

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Google and Beyond

• Your guide to the Web

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Today we will

• consider different types of resources and
  information available via the web
• evaluate web pages
• explore the advantages of using a variety of
  different tools to search the web
• learn the difference between a classified
  directory (e.g. RDN) and a search engine (e.g.
  Lycos)
• practice using a search engine (google) and
  classified directory (RDN)

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What resources can you access via the web

• Books Project Gutenberg http//promo.net/pg/index.
  html
• Journals http//www.lmu.ac.uk/lis/lss/quick_acces
  s/index.htm - Journals
• Newspapers http//www.lmu.ac.uk/lis/lss/quick_acce
  ss/newspapers/whats_avail.htmReport
• Reference sources Oxford Reference Online
  (Off-campus access requires Athens password)
  http//www.lmu.ac.uk/lis/lss/quick_reference/
• Bibliographic tools Index to Theses
  http//www.lmu.ac.uk/lis/lss/
• Library Catalogues http//www.niss.ac.uk/lis/opacs
  alpha.html

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What resources can you access via the Web (2)?

• Discussion groups and mailing lists Google Groups
  http//www.google.co.uk/
• Databases http//www.lmu.ac.uk8082/lco/php/search
  _tools.php/alpha/
• Music
• Multimedia resources The information Cycle
  http//www.libraries.psu.edu/crsweb/instruction/ip
  /infocyle.htm
• Interactive resources Multi-map
  http//www.multimap.com/
• Software

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Strengths and weaknesses of web information

• Currency e.g. http//news.bbc.co.uk
• Quality - varied .
• Large amount of information
• No consistent structure or standard - No single
  accepted control/standard or structure

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Strengths and weaknesses of web information (2)

• Instability
• Accessibility - Open 24/7
• But is it really so accessible?
• Web search tools do not comprehensively search
  the web

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How do I evaluate a Web page?

• Authority
• Currency
• Validity / Accuracy
• Audience
• Point of View/ Bias

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Authority

• Is there a contact name?
• What is the authority of the author and/or
  publisher of the Web information?
• Evidence of qualifications, experience?
• Is there any accreditation. Has the information
  been reviewed?

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Authority (2)
Examples of domains .ac www.lmu.ac.uk .edu
www.harvard.edu .gov www.leeds.gov.uk .org.uk
www.rspca.org.uk .com www.pepsi.com .co.uk www.ca
dbury.co.uk
Use the structure of a URL for clues
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Currency

• When was the information created or updated?
• Are the links up-to-date?

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Accuracy / Validity

• Are sources of information cited?
• How does the content compare to other resources?
  
• Does the site appear to be carefully edited?

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Audience

• Who is the information targeted at?
• Is the level/type of information appropriate to
  your needs?

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Point of View

• What is the point of view (bias) of the site?
• Is there any advertising?
• Who sponsored the site?  

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Evaluating web information - examples

• Feline reactions to bearded menhttp//www.improb
  able.com/airchives/classical/cat/cat.html
• Martin Luther King siteshttp//www.martinlutherki
  ng.org/
• or
• http//thekingcenter.org/

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Advantage of using different types of tools to
search the Web

• EEVL
• Excite
• Gem
• Go
• Google
• Ixquick
• Lycos
• NISS

• Adam
• AHDS
• Altavista
• Ask Jeeves
• Biz/ed
• BUBL
• Cain
• EdWeb
• EELS

OMNI RDN SOSIG
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Categories of Search Tools
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Categories of Search Tools

• Search Engine
• Automated indexing
• Relevancy ranking
• Classified Directory
• Resources selected by someone
• Subject Gateway
• Metasearch engine

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Summary

• Vast number of resources and different types of
  information.
• Web information is not organised.
• Existing web search tools do not comprehensively
  search the whole of the web.
• 4 categories of search tools. The tool that you
  choose depends on your information need. You may
  have to use more than one tool.

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The difference between a Search Engine and a
Subject Gateway

• To demonstrate the difference we will look at
  Lycos (www.lycos.co.uk) and the Resource
  Discovery Network - or RDN - (www.rdn.ac.uk)
• Example search
• House prices UK

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Resource Discovery Network (subject gateway)

• 32 results all give useful information and from
  a variety of sources company, news, government,
  educational, report, data, etc.

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Lycos (search engine)

• 50,624 results some useful information but
  majority of results are commercial pages, e.g.
  how to buy a house or estate agents.

Also a lot of irrelevant results like
www.gift-idea.co.uk/ - a Web site that sells
balloon gifts!
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How to use a Search Engine properly

• To demonstrate how to use a Search Engine
  properly we will look at Google (www.google.co.uk)

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Tips for using Google properly

• Always go to the UK based Google site - .co.uk
  and not .com
• No need to include AND between search terms
• Searches are not case sensitive
• You can do simple OR searches
• To exclude words from your search enter a minus
  sign ( ) immediately before a term or phrase

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Tips for using Google properly

• You can search for phrases by enclosing the
  search term in quotes
• Google ignores very short and/or common words. To
  search for something that contains short words
  enclose the words in quotes to make a phrase

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Using the Advanced Search in Google

• You can use the Advanced Search screen to narrow
  down your results further

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Advanced search features

• You can specify how many results to display
• You can limit your results to a specific language
• You can choose to search for results in a
  specific file format
• You can specify the date of when the Web pages
  were last updated
• You can change where your search term occurs in
  the Web page
• You may request that all of the pages come from a
  site or certain domain

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Interpreting your Google results
A
B
C
D
E
F
G
I
H
J
K
A Statistics Bar B Page Title C Text below
the Title D Description E Category F URL
of Result G Size H Cached I Similar
Pages J Indented Result K More Results
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Further Help

• Useful online help page - Google Help Central
• Other Know-it-Alls
• Assignments finding and using information
• Dissertations successful research
• Searching the Internet pages on LCO and the
  Information and Research section of S4L.
• Learning Adviser