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Chapter 3

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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  1. The Internet, Computer Networks, &Distance LearningComputers for 21st Century Educators Sixth Ed. Chapter 3

  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)

  3. The Internet • What can I do on the internet? • What can’t you do?

  4. 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)

  5. 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

  6. 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

  7. 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

  8. 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)

  9. 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

  10. 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 • user-ID@Internet-host • e.g., jdoe@aol.com

  11. 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)

  12. 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

  13. 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”

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  21. 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

  22. 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

  23. 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

  24. 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

  25. 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

  26. 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

  27. 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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