Distance Education Systems Agenda. Distance Education Systems Asynchronous Communication: Delayed ________ between teacher and student. Synchronous Communication.

Distance Education Systems

Distance Education Systems

AgendaAgenda

Distance Education Systems

Asynchronous Communication:• Delayed ________ between

teacher and student.

Synchronous Communication• Real-time ________ between

teacher and student

Asynchronous Technologies “____________ ______"

• Print-based• Audio-based

–radio–audiotape

• Video-based–broadcast television –videotape

Print-based Correspondence

Normally, learning materials (textbook, study guide) are delivered by _____.

Original form of distance education -- dates from mid-_____s.

Advantages–Learner-paced–Can be used anywhere–___ _____

Disadvantages–Limited __________–Motion cannot be shown–Tarnished _________

I opened a letter and read it. it offered me a six months' correspondence course in finger printing at a special professional discount. I dropped it into the wastebasket..."

The Big Sleep. by Raymond Chandler

"Allied Commissioners' Courses; be a detective, send for a one-volume correspondence course. No tests, no instructors, no salesmen will call. Free handcuffs and badge included as a special bonus if you act now."

Good Behavior. by Donald Westlake

Audio and Video-based Correspondence Study

Learning materials include __________________________________.

• Advantages: similar to print-based.with visual and/or audio component

• Disadvantage: limited interactivity

Interactive Telecommunications

• Audioconferencing• ________• _________ (ITFS)• Compressed ____• Fiber-optics

Audioconferencing

Teacher and students linked by telephone --a “__________ ____."

• Advantages: relatively inexpensive, flexible

• Disadvantage: lacks visual component

Satellite-based Distance Education

“_______" transmits signal to satellite in geosynchronous orbit. T_________ amplifies signal, transmits it back to earth. Signal is received by “_______" (satellite dishes)

Satellite

Advantages• Huge "f________" means programming can be

delivered virtually anywhere to virtually unlimited number of sites

Disadvantages• Very expensive to purchase and operate• Normally, video is only ___ ___ and students use

telephone to communicate with teacher

Microwave-based (ITFS) Distance Education

• Essentially, low powered ___• Special frequencies/channels• Point-to-point or _________• Line-of-sight, 25-30 miles max.• Usually one-way video, two-way audio

Advantages

• ____ ______ video• Control over who receives signal• Excellent audio and video quality• No ___________ required

Jones. et al., 1992

MicrowaveMicrowave

Disadvantages

• Transmissions affected by _______• _________ only• Limited number of __________ available

Jones. et al., 1992

Compressed Video-based Distance Education

• _____ _____ signal digitized, then:• Processed to reduce unnecessary

information transmitted• _______ telephone lines connect sites• Not full-motion--fewer than ___ images

per second

Advantages• Easy to install and use• Can be c_______ than fiber or

microwave

Disadvantages:• Motion can be _____• Video quality can be poor• Can't transmit ___-_____ video

Jones. et al., 1992

Compressed Video

Fiber Optics-based Distance Education

• Used for telephone and cable TV main t____ lines

• Only recently used for education• Cable uses optically pure _____• Transmits _____ energy

Fiber Optics

Advantages• Full-______ _____• High quality• Unaffected by _______

Disadvantages• ____ start-up costs• Slow, expensive repairs• _____-__-____ costs

Jones. et al., 1992