Internet, Networks, Distance Learning

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The Internet, Computer Networks, Distance
Learning Computers for 21st Century Educators
Sixth Ed.

• Chapter 3

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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)

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The Internet

• What can I do on the internet?
• What cant you do?

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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)

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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

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Organizing the Internet The World 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

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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

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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)

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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
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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_at_Internet-host
• e.g., jdoe_at_aol.com

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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)

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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