Earlier quoted context omitted.
>"Green" could be the color, the environmental movement, the political party, one of several people, or lots of other things It says 'train line' right in that sentence. Where is the ambiguity? even if it missed that why didn't any of the 'cta' , 'chicago' , 'train', 'run' or 'line' nudge it in the right direction. It seems to have identified 'cta' entity correctly but completely ignored that context for the next wor…
Right, this isn't ambiguous to people. But you know that CTA and Green Line are related concepts. We don't yet have a way to model all of that huge amount of common sense knowledge that people have and use to figure out what a sentence means. It's the curse of NLP, really. All the easy things are hard. (And the hard things are nigh impossible.)
I mean, if Google My Business can show me what hours and info it pulled out of my site, why can't it also suggest an editor and code snippet to use to embed that as Schema.org LD+JSON? Sorry for going off on a tangent, but it's been days since I added LD+JSON structured data and I only just yesterday learned that some parts of Google (but not the testing tool) only recognize LD+JSON inside the head of a page. There's no immediate feedback from Google whether the data I added is actually useful or not to any part of the Borg.
I think if you wanted better data, as an entity, you could easily push the engineers behind websites to give it to you. It starts with the tooling and encouragement, though.
In this specific example, I bet Google Maps via GTFS knows plenty. Now if only GTFS could be updated to use webpages and some form of Schema.org, we'd have a standard for knowledge, right? ;-) [see Footnote 3]
[0]: I'm adding the data to try and resolve a Google Maps bug where searches for "Toronto Public Library" are instantly featuring only one of the 100 branches of the library, the one closest to Toronto City Hall. Examples[1][2]. I'm now beginning to suspect NLP, since when I search for "Toronto Public Library near me" it works as intended, but when I do just "Toronto Public Library", I think it wants to find libraries closest to Toronto, and picks City Hall Branch automatically. It also is linked, strangely, to the Wikipedia entry on the Toronto Reference Library, a different branch entirely. My Schema.org is an attempt at disambiguation using parentOrganization and subOrganization references, but if the problem is the name Toronto Public Library and how Google choses to interpret that, then there's not much I can do to change it, can I?
[1]: https://www.google.ca/maps/?q=Toronto+Public+Library
[2]: https://www.google.ca/maps/?q=Toronto+Public+Library+near+No...
[3]: GTFS used to, maybe not now, but at least when I last had to read it, required mapping transit agency specifics to general Maps fields, so for example, the Heading data would lack semantic meaning but looked good in Google Maps if you put the route in it, etc.