(semi-) automatically valuable generic feedback to
learners during learning and to authors during virtual
course development, and (2) are able to provide the
authors with mechanisms to (easily) define domain
and task specific feedback to learners.
Feedback describes any communication or
procedure given to inform a learner of the accuracy
of a response, usually to an instructional question.
More general, feedback allows the comparison of
actual performance with some standard set of
performance. In technology-assisted instruction, it is
information presented to the learner after any input
with the purpose of shaping the perceptions of the
learner. Information presented via feedback in
instruction might include not only answer
correctness, but also other information such as
precision, timeliness, learning guidance, motivational
messages, background material, sequence
advisement, critical comparisons, and learning focus.
Feedback is given in the form of hints and
recommendations. Both a domain
conceptual/structural ontology as well as a
task/design ontology is used. The ontologisms are
enriched with axioms, and on the basis of the axioms
messages of various kinds can be generated when
authors violate certain specified constraints.
In our research we are generating generic, domain
and task feedback mechanisms that produce
semantically rich feedback to learners and authors
during learning and authoring. We distinguish two
types of feedback: (1) feedback given to a student
during learning, which we call student feedback, and
(2) feedback given to an author during course
authoring, which we call author feedback. The
generic feedback mechanisms use ontologisms as
arguments of the feedback engine. This is important,
because the development of feedback mechanisms is
time consuming and specialist work, and can be
reused for different ontologisms. Besides generic
feedback mechanisms we will provide mechanisms
by means of which authors can add more domain
and/or task specific feedback. In this research, we
focus on “Mobile Computing” domain.
We designed an E-Learning environment for
Mobile Computing courses, in which: (1) learners
are able to design artifacts of certain domains using
different types of languages, and (2) authors are able
to develop virtual courses. Learners as well as
authors receive semantically rich feedback during
learning, designing artifacts and developing virtual
courses.
For example, a student first has to learn the
concept (communication) network. Assume that a
network consists of links, nodes, a protocol and a
protocol driver. Each of these concepts consists of
sub-concepts. The domain ontology ‘communication
technology’ represents these in terms of a vocabulary
of concepts and a description of the relations
between the concepts (see figures 1-3). On the basis
of an education ontology, which describes the
learning tasks, the student is asked to list the
concepts and relate the concepts to each other (see
figure 1). Feedback is given about the completeness
and correctness of the list of concept and relations
using different balloon dialog patterns.
In a second step the learner is asked to design a
part of a local area network (LAN) using the network
model developed during the first step (see figures 2-
7). Instead of concepts, concrete instantiations must
be chosen and related to each other. The learner gets
feedback about the correctness of the instantiations
and the relations between the concepts using
different star/lamb/scroll dialog patterns. Some
protocols for example need a specific network
topology. There are various sequences of activities to
develop a network, each of them with its own
particular efficiency. The student gets feedback
about the chosen sequence of activities on the basis
of the task/design ontology. Further, the student
receives different types of feedback, for example
corrective/preventive feedback, critics and guiding.
All these feedback types are further customized to
the learning style of the learner.
An author develops and optimizes a virtual course
from learning fragments. He/she has to choose,
develop and/or adapt particular ontologisms and
develops related fragmented material like examples,
definitions, etc. (see figure 1). Based on analyses of
the domain, education and feedback ontologisms, the
author gets feedback, for example about: (1)
Completeness: A concept can be used but not
defined. Ideally, every concept is introduced
somewhere in the course, unless stated otherwise
already at the start of the course. This error can also
occur in the ontology for the course. (2) Timeliness:
A concept can be used before its definition. This
might not be an error if the author uses a top-down
approach rather than a bottom- up approach to
teaching, but issuing a warning is probably helpful.
Furthermore, if there is a large distance (measured
for example in number of pages, characters, or
concepts) between the use of a concept and its
definition in the top-down approach, this is probably
an error. (3) Synonyms: Concepts with different
names may have exactly the same definition. (4)
Homonyms: A concept may have multiple, different
definitions, sometimes valid depending on the
context.
The E-Learning environment consists of four
main components: a player for the student, an
HYBRID ONTOLOGY-BASED FEEDBACK E-LEARNING SYSTEM FOR MOBILE COMPUTING
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