I find this article insanely interesting. Is there software to help doctors create this decision tree these days?
Shame about the patent - why would someone do that?
Shame about the patent - why would someone do that?
[1] http://en.wikipedia.org/wiki/Expert_system [2] https://probmods.org/ [3] https://probmods.org/conditioning.html#example-causal-infere...
But Norvig also put them in context, and left me with the impression that Expert Systems were proven inferior to Bayesian approaches for a lot of the problems they had been developed for.
I can well imagine, though, that there are problems where expert systems are a good fit.
As an interaction model and as a way of guiding control flow, as a weird and different way of handling user interaction and building extensible applications, I think the EMYCIN example from PAIP is pretty cool. I've wondered how possible it could be to use something like EMYCIN to write webapps ...
http://en.wikipedia.org/wiki/Glossary_of_patent_law_terms#Au...
Anyway, the students loaded the system with rules from literature, interviews, etc and the testing started. Soon it was clear that there was mismatch between what system suggested and what doctors diagnosed. Not always but more than expected. The rules were updated and it was a bit better, but still not there. After some back and forth finally the doctors were told to speak aloud about what they are doing examining the patients - and it become clear that doctors used additional criteria, not mentioned in the interviews (when directly asked about that stuff). And even then it was not enough to explain the differences! Simply the doctors were using additional rules that they themeself were not fully aware they were using.
Sadly I don't know what happened to that project or any more details but the implications from this story always make me think... even highly trained individuals using very strict and well defined decision process end up with result that they can't fully explain! What if we could make this hidden expertize explicit to better train future doctors or just check if it is even valid?
(Wikipedia makes it sound very complex, but you can do decision tree learning from hand from tabulated data easily, it is just tedious)
There is currently some confusion about decision trees used in decision analysis because the term "decision trees" is also used in machine learning but the approach is unrelated to decision analysis.
It's usually to protect their idea, so they can use it in a product or business venture. There's some good information on patents and the way they are used on Wikipedia.