It is interesting they are using some context for each bit of knowledge, though it is rather too simple.
In my view, this is one of the under-appreciated areas of knowledge engineering. The exact context underpins the truth of every fact. "The iPhone is the best selling smartphone." is only true for certain places, and certain times. It is definitely not true before 2007, because iPhones didn't exist for sale yet. It may not be true is some country where it isn't even available.
Other facts like "Using marijuana is illegal." are also dependent on context. In some places in the United States, for example, that may be true and false simultaneously (true in the federal law context, false in the state law context).
And that's just in the real world. We will also want general reasoning systems to be able to operate in hypothetical, historical, or even fictional contexts.
Comments
It is interesting they are using some context for each bit of knowledge, though it is rather too simple.
In my view, this is one of the under-appreciated areas of knowledge engineering. The exact context underpins the truth of every fact. "The iPhone is the best selling smartphone." is only true for certain places, and certain times. It is definitely not true before 2007, because iPhones didn't exist for sale yet. It may not be true is some country where it isn't even available.
Other facts like "Using marijuana is illegal." are also dependent on context. In some places in the United States, for example, that may be true and false simultaneously (true in the federal law context, false in the state law context).
And that's just in the real world. We will also want general reasoning systems to be able to operate in hypothetical, historical, or even fictional contexts.