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Modeling educational process using expert system.
Kudrjavcev V. B., Waschik K., Strogalov A. S., Alisejtshik P. A., Peretruchin V. V.
This work deals with the problem of computer simulation of the process in not
enough formalized subject's fields. Some requirements are settled to
educational computer systems and there is given a description of the main units
of the real acting educational system "IDEA for Windows" developed on the
theoretic investigation results of authors' association
Existing computer educational systems are basically a computer compilation of
theoretic courses and exercises to them, having in the most advanced versions
appropriate audio- and video effects for illustration. In that systems the main
part is assigned to user. He is to learn subject step by step according to
system's instructions. Thus the role of computer educational system can be
characterized as a passive one. It is only the sum of knowledge in fact and
this is a considerable work for user to learn it. Practically the modeling
training process consists of three main parts: the teacher model, the learner
model and the area of their interaction, for example, the textbook with
exercises. In existing computer training systems the roles of teacher and
learner are weak and the main role belongs to textbook with exercises and a set
of instructions that indicate how to learn. On the first stage of the computer
models and training means development these systems had played the posi!
tive role and it was hardly to require from them to simulate widely the
training process including also the parts of teacher and learner.
For "IDEA" project  the main task was to create such computer educational
system that should simulate all three parts of educational process: teacher,
learner and training material. It should include means for creation models of
teacher and learner, introduce a text-book with exercises as a set of
definitely organized academic material with multimedia elements. On this base
it should be simulated the process of real education with regard for its
character features as interdependence of teacher and learner, faculties of
learner, optimum of the strategies of knowledge and exercises dosage by
teacher, memorizing rate and forgetting rate of learner, duration and stability
of his active state, etc.
We interpret teacher and learner as adaptive automata and the training
process will consist of their iterative interaction. From automaton Ц Teacher's
point of view it will be selected the optimum feeding of educational
information to automaton- Learner on the base of how learner mastered such kind
of information on the previous educational steps.
The educational system should be many-sided (if it is possible) enough for a
given subject spheres and it should be opened and can be easily enlarged in
all its main parts.
As a model class of such subject spheres we choose real languages. Thus,
these educational systems after filling them with concrete content become
computer educational systems for learning languages. According to all mentioned
above, the problem of adaptive computer teacher synthesis includes the solution
of the following main tasks:
- Development of automaton Ц Teacher.
- Development of automaton Ц Learner.
- Development of information system analogous to the text Ц book with
- Development of interface with wide services for user.
The solution of these problems is accompanied by consideration of complicated
technical questions. Following problems can be related to them:
a) Development of dynamic data-bases and knowledge- bases contained large
masses of syntactical-information with complex semantics and fuzzy logical
connections. These bases should be compact and at the same time allow to
obtain rapidly enough the necessary information.
b) Development of indication space of automaton Ц Teacher and Ц Learner states
description with pointing out functional metrical relations between them that
allow to set functions of these automata.
c) Development of optimum strategies of interaction automaton- Teacher with
automaton- Learner both with the help of automata theory and fuzzy logic and
with the help of such procedures as pattern recognition, etc.
Authors mentioned in the title of article involved have been developing these
problems. Results of the work are shown in a number of articles (see, for
example [1, 2]). A theoretic basis is automata model  of hybrid kind and
also some models and methods developed in the limits of intellectual system
theory. Investigations resulted in development of successfully working
computers model. The structure and principles of the main units acting of
computer educational system "IDEA for Windows" using expert system as "computer
teacher" is described below.
2. General structure of system "IDEA for WINDOWS"
System "IDEA for Windows" (or "IDEA") consists of the following main modules:
Academic course is a data set, necessary for training, It contains:
- Academic material Ц the description of a subject sphere in the form of
texts, images, diagrams, schemes, video, sound recordings etc.
- Training exercises for confirming knowledge and skills obtained. Receiving
of a new information can be organized of course as exercises. There isn't
precise definition between training and text exercises because the expert
system follows the educational process and therefore for making decisions the
system can use data, obtained during execution of training exercises. "IDEA"
has a permanently enlarged set of exercise types (at present Ц 20), among them
is, for example, pronunciation training, that can be used while learning
- Description of the academic course structure as a tree (or a number of
trees) of learning goals. The tree contains a global learning goal as a root ,
for example, learning academic course adoption. The knots of following level
are subgoals of this goal and in the same way up to the knots of the lowest
level Ц elementary learning goals. The example of elementary learning goal can
be a knowledge of the forms of one irregular verb. As a rule there are a few
global learning goals and, therefore a few trees corresponding to them. In the
process of languages study these goals are grammar, communication skills,
vocabulary, knowledge of standard language constructions etc. For every
learning goal it can (and for goals of the lowest level Ц must be) indicated a
collection of training and text exercises used by system for conforming or
checking up knowledge, necessary for reaching the goal.
- Guide information Ц tables, dictionary, etc.
- Collection of learning strategies. An learning strategy is a planed
sequence of exercises or learning goals.
In the same course one or another learning strategies can be selected
depending on its tasks (it can be not obliged to study all learning material,
but only some part of it). Selection of strategy is influenced on educational
conditions (frequency and duration of lessons), start knowledge of learner, a
type of learner, determined on analysis of educational process, specific events
during educational process (for example, unexpected difficulties when learning
certain material) and, perhaps, the age of learner. Thus, academic course,
containing enough amount of strategies, allow expert system to use individual
approach to learner. This is the main advantage of "IDEA" system over other
computer educational systems. Of course, during the educational process some
local deviations from strategy can occur.That connected with decisions of
expert system or learner himself , but the global task of expert system is to
guide learner along selected strategy and therefore to solve an educa!
tional problem according to this strategy.
Interface of learner
This module solves following tasks:
- Display for learner the content of academic course, all its parts mentioned
- Allow to execute exercises and during execution give an access (allowed by
course author) to reference information. For this access learner's interface
uses its navigational means or the system of hypertext references.
- Display results of exercises and recommendations of expert system.
- Give learner (or teacher examining the education) an opportunity to
interfere in the educational process, local deviated from the sequence of
exercises planed by system. Thus deviations can be:
- Temporary alternation of educational conditions. There are three conditions
depending on how the next exercise is selected: by expert system, by learner
himself after overlooking the course content or independently of previous
results next exercise is selected from current strategy.
- Alteration of current strategy.
- Pause Ц both between exercises and during its execution.
- Display educational statistics Ц executed exercises, their results, other
events, occurred during execution (excess of planed time, use of reference
information, etc.), recommendations of expert system, deviations from learning
strategy made on learner' s initiative (see "Data base of educational history).
- Give learner an idea about current state of his knowledge Ц the level of
reaching all learning goals described in the goals tree and also goals
corresponding to learning strategies.
Author system is an instrument for creation and editing of all academic course
Module of source editing and its access in learner's condition
This module provide the access of academic course data to module of learner's
interface and to author system. The access level ( possibility of overlooking
and selecting data) is determined by interface modules. Particularly, not only
learner but also author (depending on his qualification) can neither see nor
have an opportunity to edit some course parts.
Data base of educational history
This data base keeps and renews information about all events, occurred during
the educational process. This information is a basis for making decisions by
expert system and also is accessible in part to learner through his interface.
Next events are fixed:
- All executed or started exercises and interrupted exercises are fixed
- Exercises executed successfully and separate parts of exercises.
- Errors made during execution of exercises with qualification of error class.
"IDEA" uses 4 classes of errors:
- casual errors (misprints, casual pressure of "mouse" button not in necessary
- errors connected with knowledge (skills) lack of the subject learned at
- errors connected with knowledge (skills) lack of other subjects;
- unrecognized errors (for example, meaningless sequences of letters in the
place where it was necessary to write a word)
- The use of guide or another additional information.
- Considerable excess of time planed by author or, on the contrary, execution
of exercise earlier than planed before.
- Conducted on learner's initiative deviations from learning strategy and
other interferences in training process.
All mentioned above information is accessible both for separate exercises,
elementary learning goals and for upper levels of learning goals trees as an
accumulated information about subgoals.
Expert system consists of core and knowledge base of production type. The task
of expert system is to determine the tactics of conducting learner along
learning strategy and therefore to solve an educational problem according to
this strategy. Besides this, expert system corrects the behavior of learner
during educational process, giving him advices. The basis for making decisions
is the following information:
- Current information (the educational task).
- Data -base of educational history.
- Hypothesis about learner's type that is constantly corrected during
- Local events occurred in the last exercise, in current learning goal,
occurred during the last lesson or for the last hour, etc.
- Learning goals tree Ц is used if needed additional training, return to not
enough learned subject and testing knowledge after its repetition.
3. Training using expert system
Beginning the work with "IDEA" for the first time, learner must answer a
number of questions planed by the author of academic course. As a rule, these
are questions about name, age, start knowledge level of learned subject, about
knowledge in adjacent fields (for example, when learning foreign language it is
the knowledge of another one.)
It can be possible questions about goals of learner while learning the course
concerned, about intended frequency and duration of lessons etc. On the basis
of start inquest expert system recommends learner one of the learning
strategies. Each strategy contains summary that allows learner to decide
himself either follow expert system's recommendation or try to begin his
training according to another strategy. The second task of start inquest is to
give expert system information for development of preliminary hypothesis about
learner's type. During educational process this hypothesis will be corrected.
According to current hypothesis expert system will apply one or another tactics
of training. There is also another significant aspect that allows to
individualize the educational system, that is "IDEA" calls learner by name and
addresses him "you" and etc.
Course author has a possibility of using the value of that variables in
Then expert system selects the first exercise. All events occurred during its
execution are fixed in data- base of learner results. After execution of the
exercise expert system gives learner advices, explains current training
situation and proposes next exercise. In any moment learner can deviate from
proposed exercise sequence. This fact and all events occurred during such
deviations are fixed in data- base of learner results and will be used by
expert system later on when making decisions.
4. Optimization of time of making decisions by expert system
The task of optimization of time of making decisions by educational expert
system attains special importance in view of considerable volume of data and
knowledge bases and of necessity of calling expert system very frequently and
for immediately reaction on occurring events. While solving this problem the
following feature of expert system "IDEA" was used. Knowledge base uses in the
left part of productions almost all information kept in the data- base of
educational history and therefore when calculating the truth of conditions we
have to call data base every time. But the content of data -base is changing
very slowly because its main part is accumulated information about learning
goals. That's why data- base compiler creates special index structure setting
up relationship between data -base records and knowledge- base productions.
When renewing information in data Ц base of educational history, the list of
knowledge- base productions and conditions necessary to calculate is
selected immediately and this list reduced essentially the time of making
5. The language of educational history description
For expert system a special language was developed. It allows to use in
knowledge- base productions accumulated information about events kept in data
base of educational history.
The language is based on the following ideas:
- Learner type. "IDEA" doesn't use predetermined learner type and give to the
knowledge- base author (specialist) a free hand in determination of his own
types according to his methods.
- Event. Examples of events are mentioned above. The author can determine new
events calculated on the base of previously determined events.
- Interval. This is either learning goal or learning strategy, exercise, or
one of the temporal intervals, that is, the last lesson, last hour, etc.
- The type of curve. This is a description of event frequency dynamics on
interval in one or two words: frequently; seldom; first seldom then more
frequently, etc. "IDEA" uses a finite of curve types determined by author (in
the working knowledge- base there are 14 types).
- The curve weight on the interval. This is the ratio of the number of
occurred events to the number of possible events or, as in case of using guide
information to the number of expected events (in that case it can be more than
The experience of knowledge- base creations for system "IDEA" has shown that
this language reflected well the structure of specialists' knowledge on
training methods. They being acquainted with neither expert system theory nor
programming languages are able to create a working knowledge -base.
The present work is fulfilled in the limits of INTAS project "Educational
computer systems in human spheres of knowledge", N 94-135.
. Waschik K., Kudrjavcev V. B., Strogalov A. S. "Project "IDEA".
Information into the new software generation of ICB type for making a knowledge
and skills using expert system". Link & Link software GmbH., Dortmund, Germany,
1995, Ц 40 p.
 Kudrjavcev V. S., Waschik K., Strogalov A. S., Aliseytshik P. A.,
Peretruchin V. V. "Educational computer system of automatic machine type". In
the book: Problems of theoretic cybernetics, M.: Publish. center RSHU, 1996, p.
 Kudrjavcev V. B., Aleshin S. V., Podkolsin A. S. "Introduction into the
automatic-machine theory". M.: Science, 1985. Ц 319 p.
Dr. Sci. Prof. Valery Borisovitsh Kudrjavcev
Head of chair MaTIS Dept. of math. and mech.,Moscow State University
Tel.: 007-095-4347014, Fax.: 007-095-4347014,
Dr. Waschik Klaus
Vice-director Institute for russian and sovijet culture Ruhr-Uni., Bochum
44801 Bochum Germany
Tel.: +49 234-3223368 , Fax.: 0234-7094243
Dr.Sci. Associate Prof.Alexandr Sergeevitsh Strogalov
Director Moscow Scientific Center for culture and information technology
Tel.: 007-095-973-4707, Fax.: 007-095-4708888,
Dr. Pavel Alexandrovitsh Alisejtshik
Senior.Researcher , chair MaTIS Dept. of math. and mech.,
Moscow State University
Tel.: 007-095-3386073, Fax.: 007-095-9734707
Dr. Vadim Valentinovitsh Peretruchin
Leader programmer ,chair MaTIS Dept. of math. and mech.,
Moscow State University
Tel.: 007-095-3430096, Fax.: 007-095-9734707
Proc. of 2nd Russian-German Symposium New Media for Educational and Training
in Computer Science, Moscow, 1996
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