Chapter 3 Internet Agents

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Chapter 3Internet Agents
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Contents

• Background
• Web Search Agents
• Information Filtering Agents
• Notification Agents
• Other Service Agents

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Background

• The dominant form of Web usage is the direct
  manipulation method (surfing).
• The characteristics of the Web dictate why we
  need Internet agents for information brokering.
• The volume of information on the Internet is
  huge.
• The type of information on the Internet varies
  widely.
• The quality of information varies greatly.
• The depth-first surfing inherently encouraged by
  Web browser causes most users to be lost in Web
  hyper space.
• Internet agents are computer programs that reside
  on those servers and access the distributed
  on-line information on the Internet to perform
  tasks on behalf of users without direct user
  interaction.

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Background

• Categorization
• Web search agents
• Information filtering agents
• Off-line delivery agents
• Notification agents
• Service agents
• Web site agents
• Mobile agents

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Web Search Agents
Web Browser
Query Server
User
Index Database
Web
Web Robot
Also known as softbot, spiders, wanderers,
crawlers.
Search Engine
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Web Search Agents

• The performance of a search engine can be
  measured by its precision and recall.
• Precision

the document relevant to the query the total
number of document returned

• Recall

the document relevant to the query the total
number of document
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Web Robots

• The Web robot is an autonomous agent that
  communicates with the Web using, for example, the
  HTTP protocol.
• The software robots have different strategies for
  traversing the Web graph.
• Robots usually use a strategy to traverse the Web
  graph in a prioritized manner.
• Lycos uses a queue to store all the pointers in
  the page.
• Web Crawler uses a breadth-first
• Robots may exclude different types of documents
  such as pictures and binary files.

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Web Robots
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Web Robots
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Information Filtering Agents

• While search agents are useful in finding Web
  sites of particular interest to a user,
  information filtering agents find the content of
  particular interest to a user using different
  information sources.

Web Browser
News Server
Index Articles
User Profile
Web
Indexing Engine
Filtering Agent
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Information Filtering Agents

• The indexing engine binds keywords to each
  article.
• Most information retrieval systems model
  documents as terms and term frequency counts.
• Document model representations can be roughly
  divided into two groups
• Vector space models, Tree structures
• Most information retrieval systems also generate
  the thesaurus classes by synonyms in order to
  index words by word stems.
• The similarity between two documents can be
  determined by a suitable distance metric
• Term Frequency Inverse Document Frequency of
  TfIDf

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NewsHound Personalized Newspaper

• Searches the stories in the San Jose Mercury News
  as well as several other newspapers to find
  articles that match a users profile.
• Uses the Verity Topic indexing engine with an
  email and Web form style interface.
• See Fig. 3.5, p. 61

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Benefits of Information Filtering Agents

• Benefits see Table 3.4, p. 62
• What can information filtering agents do for your
  organization?
• Brings the latest HW configuration and pricing
  information for a purchasing manager
• delivers the international, financial, political,
  and economic news that impact a financial
  investment
• Tracks news related to an ongoing investigation
  for law enforcement agency personnel
• Gathers news about job market conditions for a
  special employment category for a human resources
  professional

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Off-line Delivery Agents

• Information filtering agents that deliver
  personalized information in a locally viewable
  format without requiring a direct Internet
  connection.
• When does an information filtering agent that
  delivered customized information via an email
  message become an off-line delivery agent?
• When the information agent has its own
  information delivery software on the desktop for
  automatic information delivery and management of
  delivered information.

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Off-line Delivery Agents
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Notification agents

• A notification agent notifies users of events of
  significance to them when an event is a change in
  the state of information such as
• Content change in a particular Web page
• Search engine additions for specified keyword
  queries
• User-specified reminders for special event such
  as birthday.
• Internet notification agents are typically
  server-based programs that poll user-specified
  sites.

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Notification agents

• Methods employed
• HTTP If-Modified-Since request This is a
  special Head Request that returns a document only
  if the page has been modified since the specified
  date.
• Text only retrieval Notification agents will
  retrieve only the text of a page without the
  graphics and hyperlinks, and parse the retrieved
  text to determine any change in the published
  information.
• Embedded HTML extensions These are directions to
  notification agents embedded in HTML document by
  publishers.

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Other Service Agents

• Announcement agents
• Remind users of important occasions that are
  customized for personal needs.
• Book agents
• Track newly released books that match a users
  reading interests.
• Business information monitoring agents
• Monitor the exchange of information on the
  Internet relating to services, products,
  industry, and companies.
• Classified agents
• Search a database of classified ads daily to find
  a user-specified item, and notify the user via
  mail.

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Other Service Agents

• Direct mail agents
• Bring personalized direct mail advertising that
  matches the users stated personal background,
  activities, and lifestyle.
• Financial service agents
• Deliver email messages containing price and
  financial news for a personalized portfolio of
  securities and mutual funds.
• Food and wine agents
• Remember each users previous purchases and
  tasting notes to make customized presentation of
  inventory during the next visit.
• Job agents
• Serve as virtual recruiters to find employees
  that match employer job profiles.

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Other Service Agents

• Entertainment agents
• Finds communities with similar interests to those
  of the user, and recommends albums. Movies, and
  so on based on group evaluations
• Shopping agents
• Perform comparison shopping for user-specified
  items at virtual stores.
• Site agents
• Functions as a virtual host at 3D and client sites

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Other Service Agents

• Grouping based on their internal architectures
• Agents that perform intelligent database queries
  and notify users
• Agents that use a parallel search algorithm to
  query Web resources and integrate query results
  on behalf of the user
• Agents that use collaborative filtering to find
  user clusters for recommendations based on social
  communities
• Agents that use natural language techniques to
  engage in conversations with users