Basics of the Web and Search Engines

1
Basics of the Web and Search Engines
2
The Internet is

• a major presence in our daily lives
• constantly growing
• helping make an enormous amount of information
  available

3
Browsers Search Engines

• Browsers are software that allow you to look at
  Internet content.
• Netscape, Explorer, Opera, Firefox etc.
• Search Engines are programs were you can search
  the Internet.
• Google, Yahoo
• Dogpile, Clusty, Mamma

4
More about Search Engines

• They only search a TINY section of the web and
  index it.
• Search Engines have three basic functions
• Search
• Store
• Deliver

5
Searching

• Uses spiders, robots or webcrawlers
• Software programmed by the search engine to
  follow links and to gather information
• Goes to only selected parts of the Internet
  scanning for text, links, and the URL
• It then builds a list of words where to find
  them

6
Storing

• Seach Engines create a list of keywords where
  to find them in an index
• Each Engine creates guidelines to determine what
  is stored
• Indexes for different search engines will not
  store the exact same information

(so its a good idea to use more then one search
engine)
7
Delivery (Give results)

• Search Engines matche the keywords of the user to
  the keywords in the index
• Produces a ranked list of websites, web documents
• Each search engine uses a different set of rules
  for ranking the results

So
8

• When you use a search engine, you are not
  searching the current web

but rather the index created by the search engine
to organize the information previously collected
by the spider.
9
So what are you missing?

• Everything that isnt on the surface.
• The deep Web is about 500 times bigger than the
  surface Web.
• The Deep Web is all information that is
  inaccessible through search engines.
• This would include private databases, like the
  ones the library subscribes to through Galileo.

10
Tips for searching the Internet

• Use more then one search engine for your
  searching (one engine will not get you
  everything)
• Use multiple keywords in different orders
  (indexing have different keywords and the order
  you use may indicate rank of importance)
• Dont stop looking at the first page of results
  (the ranking may have put the best link on the
  third page)

11

• For more information on how to best search Google
  and Ask, use the link on the assignment page.