Unit 1—Computer Basics
Lesson 3
The Internet and Research
Objectives

List some reasons for searching the
Internet.
 Describe different search approaches.
 Define a search engine.
 Explain how search engines work.
 Identify some of the more popular search
engines.
Computer Concepts BASICS - 2
Objectives (cont.)
List some of the specialty search
engines.
 Describe some search tips and tricks.
 Describe the subject directory search
approach.
 Describe the invisible Web.

Computer Concepts BASICS - 3
Internet Search Tools

There are two basic types of Internet
search tools:

Search engines


Subject directories


Perform searches based on keywords
Search by specialized topics
What is the difference between them?

Search engines are automated.

Directories are assembled by people.
Computer Concepts BASICS - 4
What Is a Search Engine?



Search engines are programs that allow you
to search for information.
There are hundreds of search engines on
the Internet.
Search engines allow keyword searching.



Some support concept-based searching.
Some support stemming.
The list of results returned from your search
are called hits.
Computer Concepts BASICS - 5
Search Engine Components

Search engines usually have three main
components.



The search engine program that does the
search of its database
A spider or crawler that looks for the
information in the database
The index that is built from information
returned by the spider
Computer Concepts BASICS - 6
Keyword Searches


Keyword searches look for specific words
within a Web page.
Many search engines use meta tags to
build their search index.

Meta tags are HTML tags in a Web page that
do not display, but can be used to define page
content.
Computer Concepts BASICS - 7
Keyword Searches (cont.)

Search engines also use significant
words to build their index.


Significant words may be words mentioned
near the beginning of a page or repeated
frequently throughout the page.
Some search engines claim to index all
words in a Web page.
Computer Concepts BASICS - 8
Major Search Engines

Although there are hundreds, these are
some of the more well known search
engines:




Google at google.com
Microsoft at bing.com
Yahoo at yahoo.com
Ask Jeeves at ask.com
Computer Concepts BASICS - 9
Specialty Search Engines


These also are called category-oriented
search engines.
They are commonly used for





Locating people (whitepages.com, imdb.com)
Academic research (eric.ed.gov)
Shopping (bizrate.com, froogle.com)
Travel (travelocity.com, expedia.com)
Medical information (webmd.com)
Computer Concepts BASICS - 10
Tools and Techniques for Searching

Some commonly used techniques





Phrase searching
Search engine math
Boolean searching
Wildcard searching
Title searching
Computer Concepts BASICS - 11
Phrase Searching


This is used to search for words that must
appear next to each other.
Phrases must be enclosed in double
quotation marks.



“Books on the Civil War”
Only sites with the exact phrase will be
returned as hits.
You should capitalize proper nouns.
Computer Concepts BASICS - 12
Search Engine Math

Use math symbols to enter formulas or to
filter out unwanted listings.


A plus sign (+) before a word means it must
appear.
A minus sign (-) before a word means it should
not appear.
Computer Concepts BASICS - 13
Search Engine Math (cont.)

Examples of search engine math

To search for sites that contain both cookies
and recipes, enter


+cookies+recipes
To exclude sites that have coconut cookie
recipes, enter

+cookies+recipes-coconut
Computer Concepts BASICS - 14
Boolean Searching

Boolean logic consists of three operators:




AND: Search for sites that include Word A
AND Word B.
NOT: Search for sites the include Word A
but NOT Word B.
OR: Search for sites that include Word A OR
Word B.
Can be accessed from Advanced Search
Computer Concepts BASICS - 15
Wildcard Searching


Wildcard searching allows you to search for
words for which you may not know the
spelling or to search for plurals or variations
of a word.
The wildcard character (*) lets you search
for any word that has the characters before
or after the wildcard character.
Computer Concepts BASICS - 16
Wildcard Searching (cont.)

Wildcard search example

To search for the element potassium without
knowing how it is spelled, enter


PO* or po*ium
Not all search engines support wildcard
searches.
Computer Concepts BASICS - 17
Related Searching

Some search engines have a related search
feature.
 The search engine will return hits based on
your search criteria and may also display a
list of other sites that have information related
to your search criteria.
 This can greatly improve the odds of finding
the information that you want.
 Note: Some sites call this feature similar
pages or more pages like this.
Computer Concepts BASICS - 18
Subject Directory Searching

Subject experts personally examine Web
sites and add the URL to a search engine if
it meets standards.
 Subject directories are organized by subject
categories.
 You start at the top of a category and drill
down from a generic start to a specific topic.
Computer Concepts BASICS - 19
Popular Subject Search Sites
About: about.com
 The Librarians Index: www.lii.org
 Yahoo: www.yahoo.com
 Galaxy: www.galaxy.com

Computer Concepts BASICS - 20
Advantages of Subject Directory
Searches






They usually provide a more guided
approach than keyword searches.
They are easy to use.
You are not searching the entire Web.
The linked sites have been handpicked and
evaluated.
Most links include a description.
They produce better quality hits on
searches for common items.
Computer Concepts BASICS - 21
The Invisible Web

Also known as the “deep Web”


Indexes searchable databases, such as
password-protected library databases
Resources


www.completeplanet.com
www.infomine.ucr.edu
Computer Concepts BASICS - 22
Summary




Search engines and directories are two
basic tools that you can use to find
information on the Web.
People assemble directories; search
engines are automated.
A search engine is a software program.
Most search engines support keyword
searches.
Computer Concepts BASICS - 23
Summary (cont.)



Concept-based searching occurs when the
search engine returns hits that relate to
keywords.
Stemming relates to the search engine’s
capability to find variations of a word.
Meta tags are special tags embedded in a
Web page; many search engines use the
tags to create their indexes.
Computer Concepts BASICS - 24
Summary (cont.)




Keywords describe the information you are
trying to locate.
Search engines contain a database of
organized information.
Some search engines use natural language.
A search engine has three main parts: the
search engine software, a spider that
searches for keywords, and an index.
Computer Concepts BASICS - 25
Summary (cont.)




Stop words, such as www, but, and or, are
not indexed by many search engines.
A search engine uses an algorithm to
index Web sites.
Specialized search engines focus on a
particular topic.
Multimedia search engines focus on
video, animation, graphics, and music.
Computer Concepts BASICS - 26
Summary (cont.)




Subject directories are organized by subject
categories.
Subject experts check the Web sites that
are part of a subject directory’s database.
Use double quotation marks around a set of
words for phrase searching.
Use the plus and minus signs for inclusion
and exclusion of words within a search.
Computer Concepts BASICS - 27
Summary (cont.)



Boolean searching uses the three logical
operators OR, AND, and NOT.
The * symbol is used for wildcard
searching.
No single organization indexes the entire
Internet.
Computer Concepts BASICS - 28