Sunday July 20, 2008
Intranet - Home

Internet Research Basics


SEARCH TOOLS

A search engine is software that looks for data based on some kind of criteria.  It usually does so by searching through an indexed database of websites.    Search engines pull up a list of all the sites that include a topic or match the search criteria, but don’t group them by subject. These search engines often collect the data through the use of around the clock automated programs called spiders or crawlers, which constantly search the text and the coding of websites and then add the pages to their indexed databases. Two of the largest are Google and Altavista.

A search directory is an organized collection of websites categorized by subject.  These directories are usually arranged in a hierarchical structure. A good example is Yahoo.

Web Directories are developed by real people or groups of people, not automated programs. Directories are organized by a main topic and subtopics – often referred to as hierarchical structure. You find information by drilling down levels in the hierarchy until you locate the topic you want.  (Drilling down refers to successively clicking links to access subcategories.)

Most search engines conduct exact keyword searches. You plug in a keyword and the engine shows you everything that matches that keyword, regardless of how it is used. Natural Language search engines can perform concept based searches.   A Conceptual query is one in which the search engine returns only web pages that are relevant to the topic, even if the words don’t precisely match your key words. Example: you type in the keyword “horse”, the conceptually based search engine will bring up sites that include words such as equine, mount etc.  Two well known concept-based search engines are Excite and Ask Jeeves.

Metasearch engines query several search engines and directories simultaneously.  The metasearch engine then displays the top results on a single page.  Examples: Infospace and Dogpile.

Be aware of the invisible or deep web which consists of dynamic web pages and databases.

This portion of the web is not indexed by general search engines.  Specialized search tools can help you dig into the invisible web.  To find out more about the deep web visit: http://www.brightplanet.com/


BOOLEAN LOGIC

The three main Boolean operators are : AND, NOT and OR.  They help refine your search because they specify the logical relationship between elements.

AND is used to make sure the key words are joined and both are present on the hit page.

Example: computer AND worms will give you only information about a type of computer viruses, not earthworms.

OR is used to specify that either of the words can be present on a hit page. Example: dog or pony will return pages that contain one or the other search terms.

NOT is used to eliminate pages with a certain word.  Example:  Worms NOT Computer will eliminate computer worm viruses from your results.  Most results should be about earthworms.


Mathematical Operators

Mathematical operators are symbols used to perform an operation on a value.  They can be used in place of Boolean operators. The most common mathematical operators that you will use for internet searches are plus (+) and minus (-) sign, which equivalent to the AND and NOT Boolean operators.  It is important that you remember to place the mathematical operator next to the keyword without a space, Example: Eggs  +Bacon the results will contains both search terms. Snack food  -Potato chips the results will contains snack foods but not potato chips. 


Quotation Marks

Surrounding the search term with quotation marks will limit the results to the search pages that contain an exact match for the phrase.  Example:  “Abraham Lincoln” - the search results will contain information about the president not the Jewish patriarch Abraham or Lincoln cars.


Advanced Search Engine Options

Most large search engines have a advanced search option.  It is usually located near the main search box.  If you cannot locate this option use the Help button.  You can use this option to create a very specific search by just filling in the fields you need. Example: Google or Yahoo have the Advanced Search option.


Wildcards

A wildcard character is a special type of character that you can use in a search expression to make the search more general.  Wildcard characters are typically used when you don’t know the complete word or phrase or when you don’t know how to spell a keyword.  The most common wildcard character is the asterisk (*), which represents any type of number or character.  Example: child* - the results can include child, children, childhood, etc.