Web Design/Internet Essentials

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Web Design/Internet Essentials

• Search Engines and Searching the Web

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Search Engines

• Search Engine Basics
• Formulating Searches

The Web and E-mail
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Search Engine Basics

• A Web search engine is a program designed to help
  locate information on the Web by formulating
  simple keyword queries.

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Search Engines

• A search engine is helpful in locating
  information for which you may not know the exact
  web address on
• web pages on various topics
• locating specific web pages
• images
• videos
• There are thousands of search engines available.

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Search Engines Types
Google Search engine
Lycos Directory
Alta Vista Search engine
Yahoo Directory
WebCrawler Search engine
Excite Search engine
MSN Directory
AOL Directory
HotBot Search engine
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The Different Types of Search Engines

• Although the term "search engine" is often used
  indiscriminately to describe
• Web crawler search engines
• human-powered directories
• everything in between
• they are not all the same.
• Each type of "search engine" gathers and ranks
  listings in radically different ways.

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How do search engines work

• Contains four parts
• a web crawler
• an indexing utility
• a database
• a query processor

• Web crawler combs the web to gather data
• Indexing processes the information gather by the
  crawler
• then stores key terms and URLs in a database
• Query processor allows you to access the
  database by entering keyword

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Web Crawler

• Crawler-based search engines such as Google,
  compile their listings automatically
• They "crawl" or "spider" the web, and people
  search through their listings
• Spiders scour the web on a regular basis.
• Listings are what make up the search engine's
  index or catalog
• The index can be defined as a massive electronic
  filing cabinet containing copies of every web
  page the spider finds

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Directories

• Directories depend on human editors to compile
  their listings
• Webmasters submit an address, title, and a brief
  description of their site, and the submission is
  reviewed
• After a web site makes it into a directory it is
  generally very difficult to change its search
  engine ranking

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Hybrid search engines

• Some search engines offer both crawler-based
  results and human compiled listings called
  hybrid search engines.
• They typically favor one type of listing.
• Yahoo usually displays human-powered listings.
• It also draws secondary results from Google
• which may display crawler-based results for more
  ambiguous queries

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Search Engine Basics

• Search engines require you to enter a word or
  phase, search text or keyword that describe
  the item you want to find
• They often respond with results that include
  thousands of results, whose content varies based
  on the information you are seeking.

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Formulating Searches

• Most search engines are not case sensitive
• (Shift key usage not necessary)
• Search engines ignore common words like
• (and, a, the) there is no need for them.
• To search for an exact phrase, enter it in
  quotation marks.
• When you enter multiple terms the query
  processor assumes you want to see web pages that
  contain all of your terms.
• The asterisk () is referred to as the wildcard
  charter.

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Boolean Search

• A Boolean operator is a word or symbol that
  describes a relationship between keywords,
• Helps you create a more focused query
• Ex.1 poverty and crime Ex.2 poverty and crime
  and gender

Ex.3 cats not dogs Ex.4 cats or
felines
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Boolean Logic

• Example 1 dyslexia    adults
• Example 2 radiation    -nuclear

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Key word Search
Most search engines work with keyword queries in
which you enter one or more words
Ex. Mountain Bike
Search results
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Open your browser and go to the website below and
watchThe Animated Internet How Search Engines
Work http//www.learnthenet.com/ENGLISH/animate/s
earch.html