Transcript Search Engines - Mr. Haworth`s Web Site

What are search engines?
 Tools used for locating web pages
 Automated software programs known as spiders or
bots to survey the Web and build their databases.
 SE databases are knows as the search engine index
 The best urls are returned to you as hits.
What is a URL?
 Uniform Resource Locator: a protocol for specifying
addresses on the Internet
 An address that identifies a particular file on the
Internet
 Usually consisting of the protocol, as http, followed by
the domain name
What is a domain?
 A group of computers and devices on a network that
are administered under the same protocol.
 Indicates the type of organization, geographical
location, or both
 Designated in the suffix as .com for commercial
enterprises in the U.S.
Domains to Know . . .
 .com = a commercial business
 .edu = an educational institution
 .gov = a governmental institution
 .org = a non-profit organization
 .mil = a military site
 .net = a network site
What’s the URL? The Domain?
 ftp://www. pcwebopedia.com
 http://www.pcwebopedia.com
Why would you use a Search
Engine?
 Finding information on the Web
 Looking for a Job
 Researching a topic for school or a project
 Looking for Health or Diet Information
 Making a purchase—new car, home, computer, book,
cell phone
 Locating an old Friend or an Address
 Planning a Vacation
How Large is a Search Engine?
 Some have logged the words from over 1 billion
documents (REMEMBER that there are billions of
pages on the Web.)
What Search Engine is the Biggest?
 Google with 3.3 billion pages
 Alltheweb.com with 3.1 billion pages
Some Examples
 Lycos – one of the original Ses
 Alltheweb – largest index, fastest look-up time
 AltaVista – a favorite until Google came!
 Excite – concept-based SE
How do Search Engines Work?
 Rely on computer programs called spiders or robots to
crawl the Web
 A robot is a piece of software that automatically follows
hyperlinks from one document to the next around the
Web.
 Scans its database and returns a file with links to
websites containing key words
Getting Ready to Search
 Identify the Main Concepts in your topic
 Determine the following:

Synonyms, Alternate Spellings, Variant Work Forms
 Example: hard stone, hard test or cardiac for the word heart
 Know how to use the various search tools available
 Search Engine – Alta Vista
 Subject Directory -- Yahoo
What’s the Difference between a
SE and a Subject/Web Directory?
 Less than there used to be . . .
 Today SEs have built large subject catalogues
 Subject or Web directories organize the Web into
topics and subtopics.
 Arts, Science, Health, Business, News, Entertainment
 Think of SEs as an index that enables you to seek
specific words and phrases.
When to use what?
 For broad, general information go to a subject or web
directory.
 For narrow, specific information use a Search Engine
Which would you use for this
example?
 You'd like to create your own home page on the Web,
but you don't know how to write HTML, you've never
created a graphic file, and you're not sure how you'd
post a page on the Web even if you knew how to write
one. In short, you need a lot of information on a
rather broad topic--Web publishing.
Use a Subject or Web Directory
 To find out about Web page publishing from Yahoo,
select the Computers and Internet Topic, under which
you find a subtopic on the Wide World Web. Click on
that and you find another list of subtopics, several of
which are pertinent to your search: Web Page
Authoring, CGI Scripting, Java, HTML, Page Design,
Tutorials. Selecting any of these subtopics eventually
takes you to Web pages that have been posted precisely
for the purpose of giving you the information you
need.
Use a Strategy when Searching
 Without a clear strategy, using a search engine is like
wandering aimlessly in the stacks in a library trying to
find a particular book!
Techniques to Effectively Use
Search Engines
 Identify Keywords
 Definition: A Keyword is any word on a Web page
 Breakdown the topic into key concepts; use quotation
marks to group words together
 Example: to find information about what the FCC has
said about the wireless communications industry use—

FCC
“wireless communication”
Principles for a Smart Search
Know where to look first
2. Fine tune your keywords
3. Query by example—use the help options that the SE
provides
4. Anticipate the answer
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Search Ratings by Spidap
 Google -- Biggest, Fastest, Most
Comprehensive
 Google – Most Relevant Results
 Altavista – Best Advanced Search Refinement
 Ask Jeeves for Kids – Best Search Engine for Kids
 Google – Best Directory
Remember . . .
You are smarter than a computer.
2. Use your intelligence.
3. Search Engines are fast, but dumb!
1.
Bibliography/Sources
 Using Search Engines by Deb Flanagan, 2004
 The Spider’s Apprentice by Spidap, 2007