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Implementation Issues
We have not fully understood the cognitive aspects
involved in implementing hypertext systems.
- It is very essential to understand reading and writing
models in order to understand hypertext. In addition,
we need to understand the cognitive processes involved
in argumentation and decision making. This needs
revisiting some of the cognitive models such as Toulmin
and Rittel argumentation schema and Guilford's
Structure of Intellect Model.
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Also, existing metaphors such as electronic
encyclopedia, notecards, journeys, browsing, windows,
paths, guided tours, travel holidays, and survey-type
maps are too restrictive and do not fully exploit the
true potential of hypertext. The metaphor for
hypertext should be based on "the general cognitive
model of how individuals think about complex problems."
Hypertext systems should try to exploit the basic
nature of human cognition which is essentially
organized as a semantic network of concepts linked
together by associations. This general approach allows
any individual to adopt the appropriate mental model by
employing self-generated metaphors in the context of a
specific application while the implementation itself
can be based on a general semantic model.[Balasubramanian & Turoff, 1993]
Such an approach provides navigation and analysis of the underlying
database independent of the specific application and
the different mental models of individuals.
Converting linear text to hypertext has been a classic
problem while dealing with large information spaces such
as encyclopedias, training manuals and dictionaries.
Attempts have been made to convert these printed material
both by manual and automatic means.
- Automatic conversion of text to hypertext based on
structural features alone is not sufficient. More work
is required in the area of automatic link construction
based on lexical and semantic analysis of text. The
concepts of shallow apprentice (automatic linking based
on lexical analysis) and clever apprentice (based on
semantic analysis) must be explored further. The
concept of automatic link generation based on the
pattern of previously created user-links can be
explored. Such an algorithm can use the user's Link
Profile.[Chang, 1993]
Some researchers have suggested guidelines for both
manual and automatic conversion. These guidelines
must be applied and evaluated.
Very little work has been done in exploring the use of
hypertext templates in areas
such as collaborative writing, teaching etc.
- Hypertext templates facilitate the design,
organization, and presentation of a collection of
knowledge in the form of hypertext. Templates can also
be used to capture pre-defined or well-established
relationships in organizational tasks. The specifics
of the contents within the template can be filled in by
the author.
Traditional writing is associated with implicit
guidelines backed by thousands of years of linear writing
experience. On the other hand, hypertext writing is new
to authors and it is easy to produce an incomprehensible
hypertext document.
- Researchers have suggested some general
guidelines for authoring hypertext documents. These include
dividing a hypertext document into three components: the content
part, the organizational part, and the presentation
part. Experiments must be conducted to assess the
effectiveness of such authoring guidelines in
developing large-scale hypertext systems.
Information systems such as Decision Support Systems
and Expert Systems require a dynamic implementation of
hypertext by incorporating virtual structures,
computation, and filters.
- The use of bridge laws to
generate dynamic structures
must be explored further. Tools are also required for
developers to define bridge laws easily. Dynamism can
also be achieved by employing link-resolving algorithms
which generate links to nodes based on user interaction.[Tompa et al., 1993]
For example, the user can click on a word and the system can search for the occurrence
of the same word or a synonymous word in other
documents/nodes and traverse to that node. These can
be considered non-authored link markers/links. Links
thus become similar to database keys: not only can
individual hypertext links be stored as explicit
pointers but they can also be resolved "on the fly"
through the execution of more complicated algorithms.
Very few attempts have been made to linearize hypertext
documents for the purpose of printing.
- A first step towards linearization would be an
algorithm to traverse all the nodes visited by the user
and produce a linear document. Another method would be
for the user to specify the start and end points of
linearization so that all interactions between these
two points will be linear.
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