It is generally known that expert systems and artificial intelligence seem to have become apt aids for researchers and developers. We try to prove that these systems can also become interesting for educational purposes. For an expert system can be adapted for use in education. A pupil ,student or trainee might like to consult 'experts' (as a 'tutor') in his or her study, and use CAI programs which can simulate an expert. Such CAI software, containing an expert system is called an 'intelligent CAI' (ICAI). However, expert systems in CAI or CAL context have not yet been realized, but this will undoubtedly be developed in the near future. For the discussion it is important to discern at least three kinds of expert systems:

• 1. 'Logical decision tree' systems, based on decision rules (if-then-else-like rules) which are similar to methods for determination of a plant with the help of a flora.
• 2. Systems which use calculation of probability with the help of the method of Bayes by which, for example, the probability of a symptom of an illness is turned into a probability of that syndrome when such a symptom is found.
• 3. Systems with rule and/or knowledge base which make use of special languages like Prolog, Lisp or Smalltalk.

In chapter 1 of my book (1996) (see elswhere on my WEB-site) the basic idea is described which underlying the second method described by a.o. Lusted (1968) and De Dombal (1972), using the method by Bayes. This is done on the basis of an example from the practice of a medical specialist with four syndromes in relation to seven .i.symptoms;. A non-medical subject could also have been chosen, but a medical example is perhaps more appealing, because it is a question of a diagnosis in the most ordinary sense of the word. With this expert system a diagnosis can be given (automatized) when a student answers the following questions:

1. Are you short-winded when straining?
2. Do your legs hurt?
3. Do you have pain when straining?
4. Are your feet swollen at night?
5. Is your body blue? 
6. Does it hurt in the middle of your breastbone?
7. Do you feel heavy pressure on your chest?

The most probable diagnosis is a. Astma Bronchiale
with a probability of 0.575.

The computer program containing the expert system has been developed at the University of Twente, and is called PHYSICIAN / ARTS. There are three different versions. The first version was realized on an Apple II microcomputer and is used in a lab for the third year subject 'CAL-technics' for students of the University of Twente. The second version was developed on a Macintosh computer of Apple in Macintosh Pascal and it only uses texts. The third version was also developed on Macintosh and it has the special feature that the calculated chances are always graphically represented after answering a question. Now there is a fourth online WEB-version.

This provides good visual support during diagnosing. This option is also important for 'gauging' the expert system. It is not yet quite clear how expert systems will acquire a place in education. The possibilities for the training of medical students and laboratory workers are enormous. For non-medical education there are also plenty of possibilities. Think of a training where diagnosing has to be learned, like analyzing break downs in cars or computers: so in technical education; in determination as with a flora or fauna in microbiology: at laboratory colleges; in classification and making automatic divisions: in financial, economic or judicial fields; in pattern recognition; in geology, meteorology, etc.

A reference is: Min, F.B.M., (1985); Een expertsysteem gebaseerd op kansberekening; een poging tot ontmythologisering; een 'didactisch voorbeeld'. Computers op school, jaarg. 3, no. 2, (dec. 1985), page 12-19.

At the University of Twente not only a medical example has been developed of an expert system based on this method, but also one from biochemistry that can differentiate between acute hepatitis, jaundice caused by a blockade in the bile, cirrhosis and liver metastasis, and an example from sociology that can differentiate between various political convictions.

Start

Do you want to restart and clear the form-fields?
1. Are you short-winded when straining?
2. Do your legs hurt?

3. Do you have pain when straining?
4. Are your feet swollen at night?
5. Is your body blue?
6. Does it hurt in the middle of your breastbone?
7. Do you feel heavy pressure on your chest?


a      b      c      d

So The most probable diagnosis is with a probability of (with a maximum of 1 and a minimum of 0).

The evaluation

Let op:

• 1. U moet vraag voor vraag afwerken. Er is - voor de didactische en software technische duidelijkheid - geen beveiliging ingebouwd. U mag bij een vraag yes nog een of meer maal veranderen in no en omgekeerd. U mag niet terugkeren naar een andere vraag.
• 2. Niet-ziek bestaat bij dit systeem niet.
• 3. Er is geen afhankelijkheid tussen de vragen en de ziektebeelden.
• 4. This system is for educational purposes only.

Enschede, 1988 - 2001; updated: 20 april 2001.