Activity 4

What are the advantages and disadvantages of using a search engines?

Disadvantages
1Regardless of the growing sophistication, many well thought-out search phrases produce
list after list of irrelevant web pages. The typical search still requires
sifting through dirt to find the gems.

2Using search engines does involve a learning curve. Many beginning Internet users,
because of these disadvantages, become discouraged and frustrated.

http://www.gsn.org/web/research/internet/disadse.htm
Advantages

1The indexes of search engines are usually vast, representing significant portions
of the Internet, offering a wide variety and quantity of information resources.

2The growing sophistication of search engine software enables us to precisely
describe the information that we seek.

3The large number and variety of search engines enriches the Internet,
making it at least appear to be organized.

http://www.gsn.org/web/research/internet/advtse.htm


Compare/Contrast Individual search engine and meta search engine.

Metasearch engine
A metasearch engine is a search tool that sends user requests to several other search engines
and/or databases and aggregates the results into a single list or displays them according
to their source. Metasearch engines enable users to enter search criteria once and access
several search engines simultaneously. Metasearch engines operate on the premise that the
Web is too large for any one search engine to index it all and that more comprehensive
search results can be obtained by combining the results from several search engines.
This also may save the user from having to use multiple search engines separately.
http://en.wikipedia.org/wiki/Metasearch_engine

Individual search engine
Individual Search engines index web sites using electronic means such as spiders, robots or worms which roam the
web and compile a database of information. In its basic form, the results list from a search of this
database contains a list of web sites which contain that search term, and the placement of the web sites
on that list is based upon the frequency of the appearance of that term, its location on the page and similar
factors.
http://en.wikipedia.org/wiki/Metasearch_engine


When is it appropriate to use search engine and subject directories?


Subject Directories
Subject directories are useful when you want to know more on broad-based subjects, such as:

General topics
Popular topics
Specialized Directories
Current events
Product information

Let us consider each of these in turn, but first some words about the strengths of subject directories.
They are organized and they are selective. When you are not sure of the exact term to search for,
browsing a subject directory's subject categories will help you find those keywords. This is
actually quite useful for preparing certain search engine searches. Browsing for keywords will
also provide a context for your search. Remember: subject directories are usually smaller than search engines,
have much more focused and higher quality links, but are poor for exhaustive searching.

http://www.articleinput.com/e/a/title/When-to-use-a-subject-directory-and-not-a-search-engine/


What is an invisible Web or "Deep Web"?


Invisible Web
The Deep Web (also called Deepnet, the invisible Web, DarkNet, Undernet, or the hidden Web)
refers to World Wide Web content that is not part of the Surface Web, which is
indexed by standard search engines.
http://en.wikipedia.org/wiki/Invisible_Web

How do you find invisible web?


How to find invisible web

Simply think "databases" and keep your eyes open. You can find searchable databases
 containing invisible web pages in the course of routine searching in most
general web directories.

http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/InvisibleWeb.html


Why are these not available in search engines?


Why is it deep web not visible to search engines

The "visible web" is what you can find using general web search engines. It's also what you see in almost
all subject directories. The "invisible web" is what you cannot find using these types of tools.

http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/InvisibleWeb.html