chapter 2

T e a c h e r s D i s c o v e r i n g C o m p u t e r s

Integrating Technologyin the Classroom3rd Edition

Chapter 2

Communications, Networks, the Internet, and the World Wide Web

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CHAPTER 2 OBJECTIVESCHAPTER 2 OBJECTIVES

Define communications Identify the basic components of a

communications system Describe how and why network

computers are used in schools and school districts

Explain how the Internet works

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CHAPTER 2 OBJECTIVESCHAPTER 2 OBJECTIVES

Describe the World Wide Web portion of the Internet

Explain how Web documents are linked to one another

Explain the use of Web browser software

Explain how to use a Web search tool to find information

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CHAPTER 2 OBJECTIVESCHAPTER 2 OBJECTIVES Identify several types of multimedia

products available on the Web Explain how Internet services such as e-

mail, newsgroups, chat rooms, and instant messaging work

Describe the educational implications of the Internet and the World Wide Web

Describe different ways to connect to the Internet and the World Wide Web

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WHAT IS COMMUNICATIONS?WHAT IS COMMUNICATIONS?

A process in which two or more computers or devices transfer data, instructions, and information

Sometimes called telecommunications

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WHAT IS COMMUNICATIONS?WHAT IS COMMUNICATIONS?

Electronic mail (e-mail) Voice mail Fax (facsimile) Telecommuting Online services Videoconferencing Internet World Wide Web

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COMMUNICATIONS NETWORKSCOMMUNICATIONS NETWORKS

Basic communications system• Two computers, one to send and one to

receive data• Communications devices that send and

receive data• A communications channel over which data

is sent

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A COMMUNICATIONS SYSTEMA COMMUNICATIONS SYSTEM

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Communications channel• Transmissions media

– Twisted-pair cable

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COMMUNICATIONS NETWORKS

• Digital vs. analog signals– Modem

– External modem

– Internal modem

– Network interface cards

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COMMUNICATIONS NETWORKSCOMMUNICATIONS NETWORKS Local Area Networks (LAN)

• Covers limited geographical area• Server manages resources

Wide Area Networks (WAN)• Covers large geographical area• Can consist of several LANs

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Home Networks• Connects multiple

computers in your home

• Share Internet access and resources

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NETWORKING THE CLASSROOM, SCHOOL, AND DISTRICTNETWORKING THE CLASSROOM, SCHOOL, AND DISTRICT

School network server

Example classroom• Three Macintosh

computers• Printer

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NETWORKING THE CLASSROOM, SCHOOL, AND DISTRICTNETWORKING THE CLASSROOM, SCHOOL, AND DISTRICT

Example school network• Classrooms• Administration• Computer lab

Example school district• Central office• Various schools

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SCHOOL’S LOCAL AREA NETWORK

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DISTRICT’S WIDE AREA NETWORK

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WIRELESS SCHOOLS AND CLASSROOMS

Keep in touch with family and friends from anywhere• Smart pagers• Cellular telephones• Handheld computers• Notebook computers

Wireless technology brings the computer lab to students

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HIGH SPEED OR BROADBAND ACCESS

Government works to provide high speed Internet access to classrooms

Broadband technology transmits signals at much faster speeds

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THE BENEFITS OF COMPUTER NETWORKS IN EDUCATIONTHE BENEFITS OF COMPUTER NETWORKS IN EDUCATION Sharing of computer

hardware, software, and data resources

Unlimited educational resources

Communicate with other educators and students

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WHAT IS THE INTERNET?WHAT IS THE INTERNET?

Worldwide group of connected networks that allow public access to information and services

No single organization owns or controls Estimated 500 million users Variety of uses

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The world’s largest network is the Internet, which is a worldwide collection of networks that link together millions

of businesses, governments, educational institutions, and individuals.

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HISTORY OF THE INTERNETHISTORY OF THE INTERNET

Started as a network of four computers at in both California and Utah in 1969

Advanced Research Projects Agency (ARPA) - ARPANET

More than 35 million computers today Backbone first provided by National

Science Foundation (NSF) - NSFnet

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HISTORY OF THE INTERNET

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HISTORY OF THE INTERNETHISTORY OF THE INTERNET

Backbone now provided by variety of corporations

Various organizations help define standards Internet2 (I2)

• Extremely high-speed network• Develop and test latest Internet technologies• Members include over 190 universities in the

United States, along with 60 companies and the United States government

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HOW THE INTERNET WORKSHOW THE INTERNET WORKS

Data is divided into packets Routers send packets across the

Internet Packet switching Transmission control protocol/Internet

protocol (TCP/IP) is the communications protocol used by the Internet

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Internet Service Providers versus Online Service Providers• Have permanent connections to the

Internet• Provide temporary connections to

individuals and companies for a fee• Local and national ISPs• Online service providers offer members

only areas

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Connecting to the Internet• Business or school network connected to

the Internet• Dial-up access• ISDN• Cable TV (CATV)• Digital subscriber line (DSL)

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The Internet Backbone• Acts as a highway• Local ISPs connect through leased lines

to national ISPs

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Internet Addresses • Numeric addresses• Domain name

– Domain type abbreviations– Country code abbreviations

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THE WORLD WIDE WEB (WWW)THE WORLD WIDE WEB (WWW)

Started in the early 1990s Hyperlinks Uniform Resource Locator (URL) Hypertext transfer protocol

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THE WORLD WIDE WEB (WWW)

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How a Web Page Works• Hypertext• Hyperlinks

– Target– Relative– Absolute

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• Discovery learning• Web Surfing• Webmaster• Hypertext markup language (HTML)• Web publishing

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Web Browser Software• Interprets HTML and

displays Web pages and enables you to link to other Web pages and Web sites

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Web Browser Software• Mosaic• Netscape Navigator• Microsoft Internet

Explorer

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Searching for Information on the Web• Directory maintained

by a search engine company

• Helps find information on the Web

• Search engine• Subject directory

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Multimedia on the Web• Web pages

incorporate graphics, animation, audio, video, and virtual reality

• Plug-ins

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Multimedia on the Web• Graphics

– Used to enhance text-based Internet

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– Graphics formats

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– Thumbnails

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Multimedia on the Web• Animation

– Marquees– Animated GIFs

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Multimedia on the Web• Audio

– MP3 format– MP3 player

– Streaming audio– RealAudio

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Multimedia on the Web• Video

– Streaming video– RealVideo

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Multimedia on the Web• Virtual Reality

– Simulation of real or imagined environment that appears as a three-dimensional (3-D) space

– VR worlds

49This instructional Web site uses VR to teach biology students

about cells and body tissues.

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OTHER INTERNET SERVICESOTHER INTERNET SERVICES

E-mail• Primary communication method for

both personal and business use• E-mail programs

– Mailbox– Mail server

• E-mail address– User name

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FTP (file transfer protocol)• FTP sites and

servers• Allows file downloads

and uploads• Anonymous FTP• FTP programs

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Newsgroups and Message Boards• Newsgroup – online area in which users

conduct written discussions about a particular subject– Usenet

• News server• News reader• Article• Posting• Threaded discussion

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Newsgroups and Message Boards• Message Boards – easier to use than

newsgroups

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Mailing Lists• Group of e-mail names and addresses

given a single name• Subscribing and unsubscribing• LISTSERVs

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Chat Rooms• Real-time conversation• Chat rooms• Chat clients

– IRC (Internet relay chat)– Microsoft Chat

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Instant Messaging• See when one or more

people are online• Exchange messages and

files• Join a private chat room

Short Message Service (SMS)• Send and receive text

messages from Web-enabled devices

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NETIQUETTENETIQUETTE

Internet etiquette• The code of acceptable behaviors

users should follow while on the Internet

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INTERNET SECURITYINTERNET SECURITY

Firewall Filtering software Acceptable Use Policy (AUP)

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THE IMPACT OF THE INTERNET AND THE WORLD WIDE WEB ON EDUCATION

THE IMPACT OF THE INTERNET AND THE WORLD WIDE WEB ON EDUCATION

The Web is the Gutenberg press of modern times

Collaboration with other teachers and students• ePALS

New instructional strategies

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THE FUTURE OF THE INTERNET AND THE WORLD WIDE WEBTHE FUTURE OF THE INTERNET AND THE WORLD WIDE WEB

Will connect 80 percent of the world’s computers in a few years

More than a billion wireless communication devices will be in use by the middle of the decade

All K-12 teachers will have access to the Internet in their classrooms

Wireless technology will become commonplace in K-12 education

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THE FUTURE OF THE INTERNET AND THE WORLD WIDE WEBTHE FUTURE OF THE INTERNET AND THE WORLD WIDE WEB

Everyday appliances with embedded computers will have Internet access

More intelligent and focused Web search capabilities

100 to 1,000 times faster in a few years Business will continue to be the driving

force

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THE FUTURE OF THE INTERNET AND THE WORLD WIDE WEB

Increased access speeds and greater availability will allow teachers and students to view thousands of videos

The Web will become an integral part of all education and will revolutionize the way students learn core subjects

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CHAPTER SUMMARYCHAPTER SUMMARY

Define communications Identify the basic components of a

communications system Describe how and why network

computers are used in schools and school districts

Explain how the Internet works

67

CHAPTER SUMMARYCHAPTER SUMMARY

Describe the World Wide Web portion of the Internet

Specify how Web documents are linked to one another

Explain the use of browser software Explain how to use a Web search tool

to find information

68

CHAPTER SUMMARYCHAPTER SUMMARY Identify several types of multimedia

products available on the Web Explain how Internet services, such as e-

mail, newsgroups, chat rooms, and instant messaging work

Describe the educational implications of the Internet and the World Wide Web

Describe how to connect to the Internet and the World Wide Web

T e a c h e r s D i s c o v e r i n g C o m p u t e r s

Integrating Technologyin the Classroom3rd Edition

Chapter 2 CompleteChapter 2 Complete

71

An extensive, current list of Web sites in various categories can be found at: http://www.scsite.com/tdc3

Click the Special Feature, Guide to WWW Sites link on the left sidebar

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USING A SUBJECT DIRECTORY

Provides categorized lists of links Arranged by subjects This example will show you how to find

information on Mark Twain’s childhood

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Start your browser and enter the URL www.yahoo.com in the Address box. When

the Yahoo! home page appears, point to the

Literature link below Arts & Humanities. You point to

Literature because that is the category in which Mark

Twain made his contributions.

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Click Literature. When the Literature page appears,

point to the Authors link. You point to Authors

because Mark Twain was an author. Each time you click a category link, you move

closer to the topic.

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Click Authors. When the Authors page appears, scroll down and point to the letter

T in the alphabetical site listings. (You can also find

information about Mark Twain by clicking the Literary Fiction link.)

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Click the letter T. The browser window displays an

alphabetical listing of authors whose last names begin with T, as well as

other author-related organizations that begin with

T. Scroll down and then point to the Twain, Mark

(1835-1910) link.

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Click Twain, Mark (1835-1910). When the page

appears, scroll down and then point to the Mark

Twain Papers & Project link.

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Click the Mark Twain Papers & Projects link. When the page appears,

click the links one at a time. Use the browser’s Back button to Return to The Mark Twain Papers &

Project page after viewing the page associated with

each link.

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USING A SEARCH ENGINE

Search many Web sites for information you are seeking

Carefully craft your keywords to limit the search

This example uses the Google search engine to search for the phrase, mark twain papers

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Start your browser and then enter the URL

http://www.google.comin the Address box. When

the Google home page appears, type mark twain papers in the Search text box and then point to the

Google Search button.

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Click the Google Search button. When the results of

the search appear, scroll through the links and read the descriptions. Point to the Mark Twain Papers &

Project link.

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• Click the Mark Twain Papers & Project link. A Web page appears that contains extensive information about the collected original documents by and about Mark Twain

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LIMITING THE SEARCH

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GUIDELINES TO SUCCESSFUL SEARCHING

Use nouns as keywords, and put the most important terms first in your keyword

Use the asterisk (*) to find plurals of words

Type keywords in lowercase to find both lowercase and uppercase variations

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Use quotation marks to create phrases so the search engine finds the exact sequence of words

Use a hyphen alternative• E-mail or email

Limit the search by language Use uppercase characters for Boolean

operators

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Before you use a search engine, read its Help

The Internet contains many search engines. If your search is unsuccessful with one search engine, try another

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POPULAR SEARCH SITES

Google• google.com

AllTheWeb• alltheweb.com

Yahoo!• yahoo.com

MSN Search• search.msn.com

AOL Search• search.aol.com

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POPULAR PORTALS

Ask Jeeves• askjeeves.com

HotBot• hotbot.com

Lycos• lycos.com

LookSmart• looksmart.com

AltaVista• altavista.com

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POPULAR PORTALS

Netscape Search• search.netscape.com

Overture• overture.com

InfoSpace• infospace.com

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POPULAR EDUCATION SEARCH TOOLS

Ask Jeeves for Kids• ajkids.com

Awesome Library• awesomelibrary.org

Ben’s Guide to U.S. Government for Kids• bensguide.gpo.gov

Blue Web’N• www.kn.pacbell.com/wired/bluewebn

Busy Teachers’ Web Site K-12• www.ceismc.gatech.edu/busyt

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Education Index• educationindex.com

Education World• www.education-world.com

EduHound• www.eduhound.com

emTech• www.emtech.net

FirstGov for Kids• kids.gov

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POPULAR EDUCATION SEARCH TOOLS Great Web Sites for Kids

• www.ala.org/alsc/children_links.html Kathy Schrock’s Guide for Educators

• school.discovery.com/schrockguide KidsClick!

• sunsite.berkeley.edu/KidsClick! Kid’s Search Tools

• www.rcls.org/ksearch.htm Learning Page

• learningpage.com

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Sites for Teachers• www.sitesforteachers.com

STEM-NET Theme Pages for Elementary Students and Teachers• www.stemnet.nf.ca/CUTE/themes.html

The Gateway to Educational Materials (GEM)• www.thegateway.org

TekMom’s Search Tools for Students• tekmom.com/search

Yahooligans• www.yahooligans.com

chapter 2

Documents

network computers

internet workschapter

internet services

homeshare internet access

high speed internet

communications systemdescribe

computers todaybackbone

world wide web portion