Searching the web lecture

1. EDT 251
October 22, 2009

2.  Where do you go?
 Are you happy with the results?
 Whatdo you think makes the searching
experience work well?

3.  Google – 65%
 Yahoo! – 19%
 Bing – 9%
 Ask.com – 2% and Ask Kids
 Ixquick
 Clusty
 Librarians’ Internet Index
 Google Directory
 http://infopeople.org/search/chart.html

4.  Searchengines use software (“robots” or
“spiders”) to index some amount of Web pages
• Proprietary algorithms
• Google claims over a trillion URLs searched
• Paid placement of ads provides revenue
• Currency – how frequently do they add sites?
 Other
tools add human-collected or human-
submitted sites (Google and Yahoo directories)
• These are then searched by subject or keyword
• Tend to be smaller in size
 Relevance ranking of results

5.  AKA the “Deep Web”
 Resourcesthat are not indexed by search
engines (such as library databases)
 InfoMINE– indexes free-standing
databases
 Add
term “database” to your topic in
Google or Yahoo

6.  Scholarly information subset of Google:
http://scholar.google.com
 Many journal articles included on publisher’s web sites
 Set up “Scholar Preferences”  Library Links  enter
“OhioLINK” and click to check the box
 Look for “Find it with OLinks” or “OhioLINK OLinks”
links in results

7.  Online encyclopedia of over 3 million
articles
 Built
using a wiki – allows for multiple
contributors
 How does it work?
 What are the cautions?

8. 1. Identify the important concepts
2. Choose keywords
3. Pick synonyms and related terms
4. Think about using quotes, truncation, Boolean
5. Choose a search engine
6. Read the instructions (most rules are the same, but not all)
7. Enter your search expression
8. Evaluate the results
9. Modify/narrow your search (if needed)
10. Move to a new search engine (if needed)

9.  Crucial because of fluidity/lack of standards
 Some possible criteria for any source:
• Who wrote or created the source?
• What audience was the source written for?
• Where did you (or can you) find the source?
• When was the source written or created?
• Why was the source written?
• How can you verify the information contained in
the source?
 Look carefully at URL (.com, .edu, etc.)