4. Chapter 3: Searching the
Web
Directories
A human-compiled hierarchical list of
Web pages
Organizes links in categories and
subcategories
Users drill down through categories and
subcategories to find specific information
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5. Chapter 3: Searching the
Web
Directories
A breadcrumb trail shows the hierarchical
arrangement of categories and
subcategories through which you have
clicked
Yahoo! was one of the first directories
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6. Chapter 3: Searching the
Web
Search Engines
Three major components
Spider, Bot, or Web crawler
Index
Search engine software
6
7. Chapter 3: Searching the
Web
Search Engines
A spider or bot automatically browses the
Web going from link to link to add and
update its Web page index
Search engine software compares search
keywords to index and presents search
results list
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8. Chapter 3: Searching the
Web
Search Engines
Typical information collected by a spider
Page title, URL, meta tag keywords
Occurrence of keywords in page
All of the words on the page
Internal links
Number and relevancy of other pages that
link to the page
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9. Search Engines
Search engines use different algorithms to
rank Web pages in a search results list
Most search engines also include paid or
sponsored listings on the search results
page
10. Chapter 3: Searching the
Web
Search Engines
Some search tools provide special
toolbars you can download as browser
plug-ins
10
11. Chapter 3: Searching the
Web
Meta-Search Engines
Compilesthe search results from multiple
search engines into one list
Some eliminate duplicates
Watch for paid or sponsored listings in
search results list
metacrawler
Dogpile
Mamma
Ixquick
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