edt 612 unit 2 © 2004 james lockard, peter d. abrams

EDT 612

Unit 2

© 2004 James Lockard, Peter D. Abrams

EDT 612

Unit 2


The Internet, Computer The Internet, Computer Networks, &Networks, &

Distance LearningDistance Learning

Computers for 21st Century Educators Sixth Ed.

Chapter 3Chapter 3

EDT 612

Unit 2


The Internet

• World-wide network of networks

• Millions of computers and users

• “... has made such a difference...it is

difficult to remember when we did not

depend on it….” (Roblyer, 2003)

EDT 612

Unit 2


The Internet

• What can I do on the internet?

– What can’t you do?

EDT 612

Unit 2


The Internet

• Getting Access (no computer)– Through your school

– Public access, e.g. libraries

• Getting Access (own computer)– Dial-up through your school

– Information service, e.g. AOL, MSN

– Internet service provider (ISP)

EDT 612

Unit 2


Machine Addresses• Unique for each connected computer• Two or more levels

– Separated by periods– Read right to left, general to specific– e.g. locis.loc.gov, si.edu

• Most general level = top-level domain– Examples: edu / gov / com / net / mil

• Some include country code, e.g. isbe.state.il.us

EDT 612

Unit 2


Organizing the Internet — TheThe World Wide WebWorld Wide Web

• WWW, W3 WWW, W3 (CERN, 1990)• Web ‘page’ concept

– Initially hypertext – Click on a link to navigate

• Extended to hypermedia in 1993– MOSAIC – first Web browser– ALL file types accessible (multimedia)– Non-linear navigation

EDT 612

Unit 2


INTERNET FUNCTIONS — WORLD WORLD WIDE WEBWIDE WEB

• Free Browsers– Internet Explorer – Commercial, Microsoft– Netscape – Commercial, derived from Mosaic– Mozilla – closely related to Netscape

• Others available to purchase• Client / Server

– Browser (client) runs on your computer– Client accesses multimedia files on Web servers

worldwide

EDT 612

Unit 2



• URL - Uniform Resource Locator– Web address system– Form = type://address

• http://www.cedu.niu.edu

• Types– http (most common, access to WWW)– https (secure server, for e-commerce)– others (less common)

EDT 612

Unit 2



• When URLs go “bad”– Sites come and go– URLs can change

• Solutions include– The original page gives the new URL– Work backword through the URL to the first

slash, item by item, and try each• http://www.cedu.niu.edu/~lockard/courses/ett229

XXX

EDT 612

Unit 2


INTERNET FUNCTIONS — Personal CommunicationPersonal Communication

E-MAILE-MAIL• Asynchronous communication

– Sender & receiver may ‘time-shift’– Accounts through school, ISP, free services

• World-wide range– Generally fast — seconds to a few hours– Generally no cost beyond Internet access

• Addressing– user-ID@Internet-host– e.g., [email protected]

EDT 612

Unit 2



REAL-TIME REAL-TIME (text-based)• Computer Conferencing

– Talk with keyboard, listen with monitor• Internet Relay Chat (IRC)• Multi-User Virtual Environments

– MUD (multi-user dialogue)– MOO (MUD, object oriented)– MUSE (multi-user simulation environment)

EDT 612

Unit 2



REAL-TIME REAL-TIME (non-text-based)

• Internet voice communication

– Impact on traditional phone service

• Internet for video conferencing

– Low cost alternative

– CU-SeeMe, NetMeeting, et al

EDT 612

Unit 2


INTERNET FUNCTIONS — Group CommunicationGroup Communication

DISCUSSION GROUPS (LISTS)DISCUSSION GROUPS (LISTS)

• Central system to store and forward messages– Listserv software

• Limited focus, but 1000s exist

• Personal subscription required, but free

• Messages come in your e-mail– Volume can overwhelm– Participate or “lurk”

EDT 612

Unit 2


INTERNET FUNCTIONS — Group CommunicationGroup Communication

USENET (NEWSGROUPS)USENET (NEWSGROUPS)• Another collection of discussion groups• Subscription required by Internet host

– Yours may offer only select groups– Google and AOL offer most

• Messages are ‘posted,’ not sent in e-mail– Host stores single copy of all messages

• Read messages using newsreader software– Threads organize messages by topic

EDT 612

Unit 2


INTERNET FUNCTIONS — Remote ComputingRemote Computing

• TELNETTELNET– Login to a computer from remote site– Public access sites (many library catalogs)

• Most hosts require an account– Potential email access

• FILE TRANSFER PROTOCOL (FTP)FILE TRANSFER PROTOCOL (FTP)– Download files (e.g., anonymous FTP)– Freeware (public domain)– Shareware– Software updates

EDT 612

Unit 2


TECHNICAL BACKGROUND — Computer NetworksComputer Networks

PEER NETWORK (Workgroup)PEER NETWORK (Workgroup)• Computer-based collaboration• No server — all systems are equal• Each machine has ‘public’ resources

– Share files directly– No access to ‘private’ files

• Uses standard networking hardware– Wired or wireless

EDT 612

Unit 2



LOCAL AREA NETWORK (LAN)LOCAL AREA NETWORK (LAN)

• Limited physical area

• Supports collaboration, resource sharing

– Avoid ‘sneakernet’

• Supported by master file server

– Stations share files and resources via server

EDT 612

Unit 2



LOCAL AREA NETWORK (LAN)LOCAL AREA NETWORK (LAN)

• Server may store applications– No individual software copies needed– Updated easily in one place– All users have current version always

• Can be difficult to maintain– Trained network manager needed

EDT 612

Unit 2



WIDE AREA NETWORK (WAN)WIDE AREA NETWORK (WAN)

• Consists of workstations & entire LANs

• Master server = HOST

• Cables connect local machines,

leased phone lines or wireless for LANs

• Internet = the ultimate WAN?

• Intranets

EDT 612

Unit 2


TECHNICAL BACKGROUND — Connecting to NetworksConnecting to Networks

• Network Interface– Machines connect by cable– NIC = Network Interface Card– Ethernet dominates across platforms– Fast communication, vital for WWW access

• Telephone Modems– Use existing phone lines– Convert between analog and digital– Most have fax capability, some voice mail– Slower than network interface

EDT 612

Unit 2


TECHNICAL BACKGROUND — Broadband CommunicationsBroadband Communications

• Increased bandwidth• Always connected, no

dial-up, no phone tie-up• Two competing systems

– DSL– Cable Internet– Cost significantly more than

dial-up service

EDT 612

Unit 2


TECHNICAL BACKGROUND — Broadband CommunicationsBroadband Communications

• DSL– Digital Subscriber Line (phone company)– Digital telephony, voice & data on same line– Not available everywhere

• Cable Modem– High speed and bandwidth– Uses existing cable TV system wiring– Not all cable systems offer Internet service– Performance degrades with more users– Competition concerns phone companies

EDT 612

Unit 2


TECHNICAL BACKGROUND — How the Internet WorksHow the Internet Works

• Each host connects to next nearest– Leased high speed phone lines– Minimizes cost for all users– Creates a web of connections world-wide

• Computers speak common language —TCP/IP– Transmission Control Protocol / Internet Protocol

• Every machine has unique ‘IP’ address– Numeric, e.g. 111.222.333.444– Alpha equivalents (e.g., aol.com) for convenience

EDT 612

Unit 2


Distance Learning

• Key elements– Reaching out to more learners– Learner separated from means of learning

• Time, space, or both

– Learning methods mediated by technology• Usually includes two-way communication

• Began with correspondence courses– Late 1800s

• Radio and TV courses for many years

EDT 612

Unit 2


Distance Learning

• Synonyms since the late 1990s– Web-based instruction– Online learning– E-Learning

• Blended electronic communication with Web multimedia potential

• Virtual universities and high schools• Many “systems” to create courses

EDT 612

Unit 2


Distance Learning Issues

• Effectiveness compared to face to face– No Significant Difference (NSD)– Can be viewed positively or negatively

• Lack of community– Learning in isolation differs from classroom– Requires much instructor attention

EDT 612

Unit 2


Distance Learning Issues

• Course design and delivery– Technical problems overwhelm some users– Potential lack of interaction with instructor and

other students– Requires greater self-discipline

• Easier to put off work

– Support structure absent to varying degrees– Balance flexibility with need for community

edt 612 unit 2 © 2004 james lockard, peter d. abrams

Documents