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The Internet, Computer Networks, & Distance Learning Computers for 21st Century Educators Sixth Ed. Chapter 3. The Internet. World-wide network of networks Millions of computers and users

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Chapter 3

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The internet computer networks distance learning computers for 21st century educators sixth ed

The Internet, Computer Networks, &Distance LearningComputers for 21st Century Educators Sixth Ed.

Chapter 3


The internet

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)


The internet1

The Internet

  • What can I do on the internet?

    • What can’t you do?


The internet2

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)


Machine addresses

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


Organizing the internet the world wide web

Organizing the Internet — TheWorld Wide Web

  • 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


Internet functions world wide web

INTERNET FUNCTIONS — WORLD WIDE 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


Internet functions world wide web1

INTERNET FUNCTIONS — WORLD WIDE WEB

  • 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)


Internet functions world wide web2

INTERNET FUNCTIONS — WORLD WIDE WEB

  • 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

X

X

X


Internet functions personal communication

INTERNET FUNCTIONS — Personal Communication

E-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

    • [email protected]

    • e.g., [email protected]


Internet functions personal communication1

INTERNET FUNCTIONS — Personal Communication

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)


Internet functions personal communication2

INTERNET FUNCTIONS — Personal Communication

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


Internet functions group communication

INTERNET FUNCTIONS — Group Communication

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”


Internet functions group communication1

INTERNET FUNCTIONS — Group Communication

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


Internet functions remote computing

INTERNET FUNCTIONS — Remote Computing

  • TELNET

    • 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)

    • Download files (e.g., anonymous FTP)

    • Freeware (public domain)

    • Shareware

    • Software updates


Technical background computer networks

TECHNICAL BACKGROUND — Computer Networks

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


Technical background computer networks1

TECHNICAL BACKGROUND — Computer Networks

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


Technical background computer networks2

TECHNICAL BACKGROUND — Computer Networks

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


Technical background computer networks3

TECHNICAL BACKGROUND — Computer Networks

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


Technical background connecting to networks

TECHNICAL BACKGROUND — Connecting 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


Technical background broadband communications

TECHNICAL BACKGROUND — Broadband 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


Technical background broadband communications1

TECHNICAL BACKGROUND — Broadband 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


Technical background how the internet works

TECHNICAL BACKGROUND — How 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


Distance learning

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


Distance learning1

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


Distance learning issues

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


Distance learning issues1

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


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