Search Engines: Beyond the Basics

Objectives

• How search engines work
• Advanced Google features
• Specialized search engines
• Search engine strengths and limitations

Resources

• Examples are available from the Library's Search the Web pages

• Resources include:
  • Search Engines
  • Special Search Tools
  • Image Search Engines
  • Audio Search Engines
  • Video Search Engines
  • Directories
  • Reference Sites
  • Search Engine Resources

What are Search Engines?

• System of software and hardware
• Input: Keywords, phrases, and operators
• Output: Web documents ( pages ) that match your search criteria

How do Search Engines Work?

• Spiders/Crawlers: Collect copies of web documents
• Indexers: Index where search terms appear (among other information)

• Results are arranged or ordered by ranking algorithms -> Hopefully, most relevant results come first

Search Engine Examples

• Library Search Engines page

Search Engine Results

• Are they all the same?
  • Google search for "community colleges"
  • Ask search for "community colleges"

• Paid placement & paid inclusion

Advanced Google

• Google Cheat Sheet
• Google Advanced Search Interface
• Google Web Search Features

• Guided Boolean searches
• Domain limits
• Occurrence limits (Anywhere, title, URL, links)
• "Similar to" & "Links to"
• Format limits
• Language limits

Special Googles

• Google News
  • Timely, "news"-related information
  • Get e-mail and RSS alerts
• Google Scholar
  • Configure Google Scholar to search for articles available through the C.O.D. Library
• Google Image / Google Video
  • Other image search tools / Other video search tools
• Google Maps
  • Google Maps street view

Special Search Tools

• Wikipedia (Use article "external links" like a search engine)

• del.icio.us (Search other people's "tags")

• Blog search

• Wayback Machine (Search for "lost" information)

• Even more special search tools!

Directories

Let's not forget about directories!

• Library directories page

Search Engine Strengths

• Automatic computing -> Speed and volume
• Ranking algorithms effective for many searches

Search Engine Limitations

• Volume of results
• Generally, only free parts of the web -> Quality?
• Not exhaustive -> Invisible/hidden web
  • Login/password/subscription protected sites (C.O.D. subscription databases)
  • Dynamic, query-based sites (C.O.D. Library catalog, OAIster)
  • Blocked sites
• Each indexes different parts of the web

• Results are arranged or ordered by ranking algorithms -> Hopefully, must relevant results come first

Closing

• Know the strengths and weaknesses of search engines
• Learn the advanced capabilities of one search engine
• Use other general search engines and specialized search engines when appropriate
• Carefully evaluate your results