Transcript Hypermedia and Hypertext as Agents of Change

Hypermedia and Hypertext as
Agents of Change
Dr. Christopher Staff
([email protected])
Dept. Computer Science & AI
Faculty of Science
http://www.cs.um.edu.mt/~cstaff/courses/med/med.ppt
Lecture Outline
• This lecture…
– Multimedia/hypermedia (ICT) have been
vaunted as technologies which will change the
way we learn for the better
– But how good are we humans at making
accurate predictions?
Lecture Outline
– To understand the potential of
multimedia/hypermedia, we will look at their
history
– And because this is about ICT in Education we
will also briefly cover the history of ComputerBased Learning (Computer-Aided Instruction, Distance
Learning, Intelligent Tutoring Systems, eLearning, …)
Lecture Outline
• Next lecture…
– Factors to consider in eLearning
– Overview of Intelligent Tutoring Systems
– Changing roles of student and tutor/teacher
Predictions Gone Wrong
• "I think there is a
world market for
maybe five
computers." Thomas Watson,
chairman of IBM,
1943
Predictions Gone Wrong
• "There is no reason
anyone would want a
computer in their
home."Ken Olson, President,
Chairman/Founder of
Digital Equipment
Corp.,1977.
Predictions Gone Wrong
“Fellow men! I promise to show the means of creating a
paradise within ten years, where everything desirable for
human life may be had by every man in superabundance,
without labour, and without pay; where the whole face of
nature shall be changed into the most beautiful of forms,
and man may live in the most magnificent palaces, in all
imaginable refinements of luxury, and in the most delightful
gardens; where he may accomplish, without labour, in one
year, more than hitherto could be done in thousands of
years.” Writer, J.A. Etzler in 1842 about the steam engine.
Predictions Gone Wrong
"De Forest has said in many newspapers and over
his signature that it would be possible to transmit
human voice across the Atlantic before many
years. Based on these absurd and deliberately
misleading statements, the misguided public...has
been persuaded to purchase stock in his
company...” District Attorney, State vs. Lee de Forest, 1913. (de Forest invented the audion tube)
(from http://www.foresight.org/News/negativeComments.html)
Predictions about Multimedia
and Hypermedia in Education
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Edutainment creates students eager to learn
Students can be given closer attention
Knowledge retention rates will be higher
Students can receive education wherever
and whenever they like
• Students can choose their own learning path
• The demise of the classroom-based teacher
Who said this and about what?
“Those who acquire it will cease to exercise their
memory and become forgetful; they will rely on
[it] to bring things to their remembrance by
external signs instead of on their own resources…
it shows great folly… to suppose that one can
transmit or acquire clear and certain knowledge of
an art through the medium …, or that … [they]
can do more than remind the … [person] of what
he knows on any given subject”
Plato, on Writing
“Those who acquire it will cease to exercise their
memory and become forgetful; they will rely on
writing to bring things to their remembrance by
external signs instead of on their own resources…
it shows great folly… to suppose that one can
transmit or acquire clear and certain knowledge of
an art through the medium of writing, or that
written words can do more than remind the reader
of what he knows on any given subject”
Plato, c. 360BC (cited in Russell, 2001)
The History of…
• Hypermedia
• Multimedia
• Computer-based Learning
Some definitions
• Multimedia
“The co-occurrence of discrete and continuous
data”
We are multi-sensory beings
We expect to receive information via
multiple, simultaneous, complementary
media
Some definitions
• Hypertext
“non-sequential writing” Nelson, T. 1987. Literary
Machines.
We are familiar with non-linear sequences
of information (dictionary, encyclopaedia,
newspaper)
(Hypermedia = Hypertext + Multimedia)
Psychology of Perception
• We have a narrow sense of perception
• Our senses are tuned to alert us to “danger”
• Processing information in our visual, aural,
etc., fields is expensive
• Our bodies are designed to process
information efficiently and effectively
“Cost” of multimedia processing
• Graphics: resolution x colour depth
– E.g., 640 x 480 x 24 = 900KB
• Video: res x colour depth x fps x duration
– 640 x 480 x 24 x 25fps x 1 sec = 21.97MB
Principles
• Hypertext/hypermedia should be designed
for efficiency and effectiveness
• Instead, information is “hidden” from us
and we must make decisions about whether
to read it
• Can actually increase cognitive load!
• Adaptive hypertext…
History of Hypertext
• 1945: Vannevar Bush describes “memex”
(Atlantic Monthly)
• 1962: Engelbart describes AUGMENT
• 1965: Ted Nelson coins the term “hypertext”
• 1968: Van Dam + others at Brown University
develop Hypertext Editing System and File
Retrieval and Editing System
History of Hypertext
• 1983: First 2nd generation hypertext
systems - Intermedia and KMS
• 1985: Peter Brown, University of Kent,
develops first commercially available
hypertext - Guide
• 1987: Prototype of Nelson’s Project Xanadu
• 1986-1990: More sophisticated hypertext
systems developed
History of Hypertext
• 1991: Tim Berners-Lee builds IP-based
distributed hypertext system at CERN
Develops UDI/URI, HTTP, and HTML…
• 1993: Mosaic, first graphical Web browser,
released
• 2002: Work begins on Semantic Web
• 2003: Proposals for Adaptive Web
Hypertext meets Multimedia
• History of multimedia dependant mainly on
wide-spread availability of “home”
computers able to support non-textual data
• Introduction of CD-ROM was an important
step (cheaply available mass storage)
• Hypermedia should allow links into and out
of non-textual data…
Computer-based Learning
• Early systems used “flash cards”
• Students tested at end of session: failures
were re-exposed to material
• In 1987, Wenger criticises computer-based
learning systems and identifies their implicit
and explicit goals
• Leads to development of modern Intelligent
Tutoring Systems
Computer-based Learning
• Wenger’s “dream” incorporates hypermedia:
“imagine active books that can interact with the reader to
communicate knowledge at the appropriate level,
selectively highlighting the interconnectedness and
ramifications of items, recalling relevant information,
probing understanding, explaining difficult areas in more
depth, skipping over seemingly known material ...
intelligent knowledge communication systems are indeed
an attractive dream”
Wenger, E. 1987. Artificial Intelligence and Tutoring Systems
Computer-based Learning
• It is little surprise, then, that modern
Adaptive Hypertext Systems have some of
their roots in Intelligent Tutoring Systems…
Agent of Change
"ICT is not an end in itself or an
agent of change by itself but when
incorporated into a well managed
change process it is a powerful
enabler and amplifier."
Bryn Jones,
http://www.apple.com.au/education/k12/ade/biographies/.
See also A learning technologies guidebook,
http://purple.nd.edu.au/coms/bj/techplan/ltguide.htm
End of first lecture
Agent of Change
"ICT is not an end in itself or an
agent of change by itself but when
incorporated into a well managed
change process it is a powerful
enabler and amplifier."
Bryn Jones,
http://www.apple.com.au/education/k12/ade/biographies/.
See also A learning technologies guidebook,
http://purple.nd.edu.au/coms/bj/techplan/ltguide.htm
Immediacy and Insatiability
• New media, new communication platforms,
mobile telephony, everything connected all the
time…
• Mediated experiences…
• … have created an expectation that every desire,
every wish, every demand, can and shall be
satisfied instantly
• The same expectations now exist in education…
ICT in the Classroom and
eLearning
ICT in the Classroom
• Introduced with the promise that children,
normally in primary, secondary schools, will
receive a better education
• Not the focus of this lecture…
• … but educational programmes are only as good
as the designers who make them, and the teachers
who use them
• The mere presence of a computer in a classroom
does not create better students…
“The future of interactive media in
education… is that of communication tool”
Radford, A. “The Future of Multimedia in Education”
eLearning
• Connecting tutors and students who cannot
be in the same place at the same time…
• Giving remote students access to support
• Shifting some of the responsibility for
“education” onto computers
Factors
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Student motivation/discipline
Student can communicate well in writing
Student potentially in control of their learning path
Tutor/Teacher as guide/learning manager
"Computer" responsible for knowledge transfer
Don't lose sight of the human element. We are
social animals!
• Computer vs. human in control of pedagogy
• Many courses are designed by others and given to
teachers to deliver (e.g., BTEC Edexcel at MCAST, NCC at Swatar, etc.)
Degrees of Support
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From video streaming individual lectures…
… to fully-fledged ITS
From individual self-contained courses…
… to full degrees from on-line Universities
Ellul, 2001: My Virtual Classroom
Virtual University
Intelligent Tutoring Systems
• Student learns by problem solving
• ITS selects a problem
– compares solution to student’s
• Performs diagnosis based on the
differences
• Gives feedback, reassesses
student and updates the student
skills model
• ITS also considers what the
student needs to know, which part
of the curriculum to teach next,
and how to present the material
• It then selects the next problem
Intelligent Tutoring Systems
Intelligent Tutoring Systems
• ITS is responsible for:
– Knowledge communication
– Student assessment
– Pedagogy
Intelligent Tutoring Systems
• ITS must know the aims, objectives, goals of the
student
• ITS must know the current knowledge of the
student
• ITS must know about the domain
• ITS must devise a plan to move the student from
current state to desired state
• ITS must be able to assess the student’s progress
Domain Expert
• The ITS must know the domain
• It must know how knowledge items are
related
• It must be able to represent interdependencies between knowledge items
• Assumption that Domain Expert represents
(complete) knowledge of the domain, and
that the student’s goal is to acquire (all of) it
Domain Expert
• Domain expertise must be machine
processable, to allow system to “reason”
• Common representation formats include:
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–
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If-Then rules
If-Then rules with uncertainty measures
Semantic networks
Frame-based Representations (Cases)
Modelling the student
• Need to represent student’s knowledge
• Need to record student’s progress
• Ideally, when student makes mistakes, ITS
can automatically discover why and take
remedial action
Modelling the student
• Student model can gather information
implicitly or explicitly
• Must compare student’s knowledge to the
expert’s knowledge (usually to highlight
differences)
• If differences indicate misconceptions, ITS
must decide how to take remedial action
Student Model Architectures
• Overlay
• Differential
• Perturbation
Overlay Student Models
• Teaching material represented as prerequisite
hierarchy
• Student’s knowledge assumed to be subset of
expert’s
• Goal is to move student’s knowledge to expert’s
knowledge
• No mechanism to differentiate between knowledge
S doesn’t understand and S hasn’t yet been
exposed to
Differential Student Models
• Distinguishes between Knowledge S does
not understand and K S has not been
exposed to
• Does not cater for misconceptions or “bugs”
Perturbation Student Models
• Caters for K possessed by S which is not in
Expert’s knowledge
• E’s domain knowledge is extended with
“bug library”
– “Bugs” are typical mistakes made by students
– Bug lib. can either be list of bugs (enumerative)
or generated from an underlying cognitive
theory (generative)
Student Model Diagnosis
• Performance measuring
– “Test”
• Model tracing
• Issue tracing
• Expert systems
Model Tracing
• Gives advice when student diverges from
acceptable solution paths
• Aims to change student behaviour
Issue Tracing
• Variation of model tracing
• Problem solving episode is analysed to
determine which skills or issues have been
used
• Does not require deep model of problem
solving
Expert Systems
• Used to analyse answers/conclusions drawn
by student
• Conclusions of ES are used to maintain
student model
Pedagogical Expertise
• Used to decide how to
• present/sequence information
• answer questions/give explanations
• provide help/guidance/remediation
Pedagogical Expertise
According to Wenger, when "learning is
viewed as successive transitions between
knowledge states, the purpose of teaching is
accordingly to facilitate the student's
traversal of the space of knowledge states."
(Wenger, E., 1987, p. 365)
Pedagogical Expertise
• The ITS must model the student's current
knowledge and support the transition to a
new knowledge state.
• ITSs must alternate between diagnostic and
didactic support.
Diagnostic Support
• Information about a student's state is
inferred on 3 levels
– Behavioural - ignores learner's knowledge,
and concentrates on observed behaviour
– Epistemic - attempts to infer learner's
knowledge state based on learner's behaviour
– Individual - cognitive model of learner's state,
attitudes (to self, world, ITS), motivation
Didactic Support
• Concerned with the "delivery" aspect of
teaching
The changing roles of teacher and student
• Assume that ICT enables dislocated
students to gain access to educational
material that would have otherwise required
(face-to-face) access to a tutor:
• How are the roles of tutor/teacher and
student changed?
How is the student likely to change?
• Learn independently?
• Learn outside the classroom?
• Student does not start as an “empty vessel”
to be filled with teacher’s knowledge (but
compare with ITS models!)
• “Active participants and partners in the
learning process”
How will teacher/tutor change?
• Traditionally, in the classroom, the teacher is
normally the “sage on the stage”
• With students changing the way they learn,
teachers will become”the guide from the side”
• Questioning, investigation,problem solving, rather
than basic “knowledge communication” likely to
become main classroom activities
http://ausweb.scu.edu.au/aw96/educn/carrucan/
http://www.apple.com/ca/education/huron/
How will teacher/tutor change?
• Identifying “knowledge trails” through
hyperspace
• Teaching how to be good discriminators of
information
How will teacher/tutor change?
• When the learning is performed at a
distance, there may be no face-to-face
contact
• But remember that technology should be
used to improve communications, not
worsen it!
How will teacher/tutor change?
• Students need greater support, otherwise
they will feel isolated
• Demotivated students need to be identified
and supported
• Students cannot (yet!) be supervised while
they accomplish some task - diminished
opportunity for correcting mistakes as they
occur
Technology
• Reliable technology may also be essential
• Increased frustration with technology may
reduce the desire to learn
Conclusion
"What we cannot expect from ICT is a universal
panacea that can be poured into schools to raise
standards. The impact that using ICT has depends on
what you do with it, and what you hope to achieve.
Much of the evidence suggests that the learning
benefits are skills rather than knowledge oriented,
and may not be captured by current assessment
methods. If that is so, the question will be do we
change the use of the ICT, or do we change the
assessment?”
http://www.schoolzone.co.uk/teachers/jft/GoodPractice/classroom/ICT/Expect.htm