Diagnostic Expert Systems

Did you ever need an expert? For anything like medical help, car repair, financial advice, or perhaps even for areas that not many other people would even understand. Imagine we could take the knowledge from such an expert, put it into a computer and let the computer help with the decision.

Perhaps not make the decision, but to support a human in making a decision - that's why this area of programs is called decision support systems, since they support the decision, but the human takes the responsibility.

The idea of extracting the body of knowledge from a human expert to computer processable form was developed by Edward Feigenbaum, starting around 1965, who also described the expert system as follows:

"Expert systems are computer programs simulating decision activity of an expert solving complex tasks and using properly coded, explicitly expressed special knowledge taken from the expert, with the goal of achieving in a selected problem area quality of decision at the level of an expert"

This may seem a complicated description, so let's have a look at several examples that would make this clear. However, let's start with a bit of expert systems terminology first.

Note: The text, images and the implementation of examples were created by Marek Obitko based on his master thesis "Diagnostic Expert System" defended in 2000.