Transcript Chapter 1 - The Internet Has Arrived

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Chapter 25 - Automated Web Search
(Search Engines)
Introduction
A Description Of Functionality
Browsing Vs. Automated Searching
A Search Tool Helps Users Get Started
– Because the Internet is vast, finding information on a
given topic can be difficult. Automated search tools
help users by finding a set of pages that contain
information related to the topic.
• A Search Tool Can Help Recover From Loss
• Automated Searching By Name
Chapter 25 - Automated Web Search
(Search Engines)
• How An Automated Search Service Operates
– Because each search server gathers information and
stores it on a local disk, the server does not need to
search computers on the Internet when responding to a
user's request.
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Modern Systems Search Web Page Contents
How A Web Search Appears To A User
How A Search Service Returns Results
Automated Search Services Use String Matching
The Advantages And Disadvantages Of String
Matching
Chapter 25 - Automated Web Search
(Search Engines)
• Advanced Search Programs That Use Multiple
Keys
• Advanced Services Offer More Sophisticated
Matching
– Because it has no intelligence, an automated search
system cannot recognize common phrsases.
Consequently, a user must be careful to remember that,
unless otherwise specified, each word will be treated as
an independent search item.
Chapter 25 - Automated Web Search
(Search Engines)
• Personalized Search Results
– Some search engines keep information about users and
use the information to select and order search results.
As a consequence, the personalized search results that a
user obtains may differ from the results another user
obtains for the same request.
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How An Automated Content Search Works
Searches Are Restricted
Examples Of Automated Search Services
Advertising Pays For Searching
• Significance Of Automated Web Search
Chapter 25 - Automated Web Search
(Search Engines)
• Terms
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contents search
document scanning
automated search service
search key
string matching
title search