Collaborative Development of Educational Modules - E-Infrastructures and Technologies for Lifelong Learning - page 197

Didactic Model tives - to motivate the study of the topic, or

to illustrate its use.
• Exploratory : Allows the learner to navigate
through the domain, practicing concepts
and other relevant information. Guided ex-
ercises, simulations and hands-on assign-
ments are representative of this category.
• Evaluative : Allows assessing the learner's
proficiency on the domain. Diagnostic,
formative and summative evaluations, in
terms of subjective and/or objective ques-
tions, are examples of evaluative elements.

The Didactic Model is responsible for the es-
tablishment of prerequisites and sequences of
presentation among conceptual and instructional
elements. In short, it can be used to illustrate the
way the didactic space is modified while being
navigated by the user, i.e., which information
becomes active/inactive when a given path is
traversed. Moreover, it is useful to represent dy-
namic contexts of learning, where the elements of
the content are determined according to specific
parameters defined in terms of the characteristics
of the course, learners and instructors.
Since HMBS addresses relevant requirements
under the didactic perspective (history mecha-
nisms, event propagation and learning contexts
definition), it was adopted in order to construct
the didactic model. Additionally, by using HMBS
we can validate the educational content through
the analysis of the subjacent statechart properties
(Turine et al., 1997).
As an extension to HMBS at the didactic level
of IMA-CID, we introduced the idea of open
specifications , providing support for the defini-
tion of dynamic contexts of learning. Depending
on aspects such as audience, learning goals and
course length, distinct ways for presenting and
navigating through the same content can be re-
quired. An open specification allows representing
all sequences of presentation in the same didactic
model. So, from a single model, several versions
of the same content can be generated according
to different pedagogical aspects. Moreover, when
an educational module is implemented based on
an open specification, its navigation paths can
be defined by the user (the instructor, in the case
of traditional classes; the learner, in distance
and active environments; or both, in the case of
blended learning), in “execution time”. During
the presentation, the user is able to dynamically
decide which topics should be navigated and in
which sequence based on the based on the learner's
skills, understanding and feedback, for instance.

As a support to construct the instructional
model, we adopted the HMBS (Hypertext Model
Based on Statecharts) model (Turine et al., 1997).
In short, HMBS uses the structure and execution
semantics of statecharts to specify the structural
organization and the browsing semantics of hy-
perdocuments. We focused on the mechanisms
for hierarchical decomposition HMBS provides,
complementing the idea of hierarchical organiza-
tion, already explored in the conceptual model. To
make HMBS suitable for modeling the instruc-
tional aspects, it was extended for representing
the different knowledge categories , i.e., concepts,
information items and instructional elements.
We highlight that IMA-CID does not prescribe
the use of the Merrill's knowledge categories as
mandatory. For instance, a user of AIM-CID could
adopt the Michener's categories (Michener, 1978),
structuring the information content into concepts,
results and examples. Actually, regardless of the
theory or technique adopted, the main goal is to
provide adequate mechanisms to specify and dif-
ferentiate the information, avoiding inconsisten-
cies and/or ambiguities. The flexibility of choos-
ing the knowledge categories to be represented
aims to guarantee the modeling approach to be
independent of particular learning theories and/
or principles, which can be defined according to
the author's preferences and needs.