Transcript Lesson 4 Researching on the Internet

Living Online Lesson 4
Using the Internet
IC3 Basics
Internet and Computing Core Certification
Ambrose, Bergerud, Buscge, Morrison, Wells-Pusins
The Internet
• The Internet contains a wealth of information.
You can find information on just about anything
that you can imagine.
• The Internet contains so much information that
it can be difficult to locate just what you need.
The Key to a Successful Search
•
Today, we live in the information age and the amount of information continues to
grow at a fast rate.
•
It can be challenging to do an effective online search on a particular topic because you
can be overwhelmed by all the data.
•
A key to a successful Internet search is an understanding of the many tools available.
•
There are two basic tools that can be used for finding information, search engines
and subject directories.
•
You use a search engine to search for keywords and you use a search directory to find
specialized topics.
•
The primary difference between these two search tools is that people assemble
directories and search engines are automated.
The Key to a Successful Search
(cont’d.)
• No single web tool indexes or organizes the whole Web.
• When you are using an online search tool, you are searching and
viewing data extracted from the Web.
• The data has been placed into the search engine’s database.
• It is the database that is searched, not the web itself. That is one
reason you get different results when you use different search
engines.
Why Search the Internet?
People search the Internet for many reasons. Some
examples are:
– Research for a paper due in class
– Finding information on a particular topic, such as “hearing
loss” for yourself or a loved one
– Planning a trip and finding information on places to stay.
Introducing Search Engines
•
A search engine is a software program that helps you locate information on the
Internet. There are hundreds of search engines throughout the Internet.
•
Each search engine may work a little differently but they do have some common
search features. For example, all search engines support keyword searches.
•
The search engine tries to figure out what you mean and returns hits on web sites that
relate to keywords.
•
Hits are the number of returns or web sites that are found based on your keywords.
•
If you search for “video games”, the search engine may also return hits on sites that
contain Nintendo and Playstation.
•
Excite is an example of a search engine. It uses ICE ( intelligent concept extraction) to
learn about word relationships.
Keyword Searches
• Keyword Searches let you search for keywords within a Web document.
• The web page author can specify these keywords using meta tags within the
web page document.
• Meta tags are special tags embedded within the web page document. They do
not affect how the page displays.
• Many search engines use these tags to create the index. For example, if your
web site is about Nintendo 64, your meta tag may look like this:
<meta name=“keywords" content=“Nintendo 64, Mario, James Bond,
Donkey Kong”>
• If a web page author doesn’t specify meta tags, the search engine evaluates
the document and indexes “significant” words.
Keyword Searches (cont’d.)
• How does a search engine find all of those web sites?
– The search engine program or software itself is the main component. The
program searches through the millions of records stored in its database.
– The spider or crawler is a search engine robot that searches the Internet
for key words. It feeds the pages it finds to the search engine.
– When the spider finds a page, it submits it to the index. Once a web page
is indexed, it becomes available to anyone using that search engine.
• When web developers register their sites with search engines,
they normally provide a list of keywords that will help get their
site on a user’s search results list.
Popular Search Engines
SEARCH ENGINE
Lycos
Yahoo
AltaVista
Google
Infoseek
Excite
WebCrawler
AlltheWeb
Northern Light
URL
www.lycos.com
www.yahoo.com
www.altavista.com
www.google.com
www.infoseek.com
www.excite.com
www.webcrawlwe.com
www.alltheweb.com
www.northernlight.com
Specialty Search Engines
• There are specialty search engines, sometimes called
category-oriented search tools that focus on a particular
topic. Here are some examples:
–
–
–
–
–
Maps and Travel information- www.expedia com
People and Companies- www.yellowpages.com
Companies and Careers- www.monster.com
World Data-www.worldbank.org
Music-www.mp3.lycos.com
Tools and Techniques for Searching
the Web
• Phrase searching-a phrase is entered using double quotation marks
and only matches.
– For example, if you are searching for information on baseball
cards, type “baseball cards” and the results will contain web sites with
the words “baseball cards” adjacent to each other, instead of
searches for baseball and cards.
• Search engine math-allows you to use math symbols to enter a
formula to filter out unwanted listings For example:
– Put a plus sign (+) before the words that must appear
– Put a minus sign (-)_before words that you do not want to appear.
If you are looking for cookie recipes, you would type
+cookies+recipes.
Tools and Techniques for Searching
the Web (cont’d.)
• Boolean searching is another way that you can
search databases.
– Boolean logic consists of three logical operators:
AND, NOT, and OR. For example, if you are
searching for cookie recipes, you would type
“cookies AND recipes” or if you wanted to search
for chocolate cookie recipes without coconut, you
would type “cookies AND recipes AND chocolate NOT
coconut.
Tools and Techniques for Searching
the Web (cont’d.)
• Wildcard Searching
• Title Searching
• Related Search
Spamming
• Internet spam is defined as electronic junk mail or junk newsgroup
postings, or even unsolicited e-mail.
• The unsolicited e-mail is most likely some type of advertising or getrich scheme.
• Spam is similar to receiving a postage-due letter. Even though you do
not pay postage when it arrives, you pay for it indirectly in the form of
disk space connect time, or even long distance net connections.
• Spam is not illegal yet, but several groups are trying to stop it. Several
states are attempting to ban unsolicited e-mails.
• You can limit spam by contacting a service that exists to take
complaints about spam, get spam-blocking and filtering services to get
programs that hide your e-mail address form potential spammers.