zlacker

Symbolic knowledge representation and reasoning is a quite interesting field. I think the design choices of projects like wikidata.org and CYC severely limit the application of this though.

For example, on the wikidata help page, they talk about the height of Mount Everest:

https://www.wikidata.org/wiki/Help:About_data#Structuring_da...

    Earth (Q2) (item) → highest point (P610) (property) → Mount Everest (Q513) (value)

and

    Mount Everest (Q513) (item) → instance of (P31) (property) → mountain (Q8502) (value)

So that's all fine, but it misses a lot of context. These facts might be true for the real world, right now, but they won't always be true. Even in the not-so-distant past, the height of Everest was lower, because of tectonic plate movement. And maybe in the future it will go even higher due to tectonics, or maybe it will go lower due to erosion.

Context awareness gets even more important when talking about facts like "the iPhone is the best selling phone", for example. That might be true right now, but it certainly wasn't true back in 2006, before the phone was released.

Context also comes in many forms, which can be necessary for useful reasoning. For example, consider the question: "What would be the highest mountain in the world, if someone blew up the peak of Everest with a bomb?" This question isn't about the real world, right here and right now, it is about a hypothetical world that doesn't exist.

Going a little further afield, you may want to ask a question like "Who is the best captain of the Enterprise?". This might be about the actual US Navy CVN-64 ship named "Enterprise", the planned CVN-80, or the older ship CV-6 Enterprise which fought in WW2. Or maybe a relevant context to the question was "Star Trek", and we're in one of several fictional worlds instead, which would result in a completely different set of facts.

I think some ability to deal with uncertainly (as with Probabilistic Graphical Models) is also necessary to deal with practical applications of this technology. We may be dealing with a mix of "objective facts" (well, let's not get into a discussion about the philosophy of science) and other facts that we may not be so certain about.

It seems to me that successful symbolic reasoning system will be very, very large and complex. I'm not at all sure even how such knowledge should be represented, never mind the issue of trying to capture it all in digital form.