I don't think it does much of any contextualization. It might recognize 'forest' as a specific type of feature, but I believe it would only use that to prioritize results, not exclude them (but I haven't taken the time to figure out how to check this).
Photon is another search system that uses OSM data:
http://wiki.openstreetmap.org/wiki/Photon
I guess Komoot uses it:
It succeeds with "Sambisa Forest".
And if no results are found, Google, please tell me "no results found" rather than giving me junk to scan to figure why did Google return me all this when it does not even have the keywords I asked for. I do not like to type a + before every keyword.
FYI, the + prefix operator was deprecated a few years ago. There was always an equivalent way to express it, by putting "each" "word" "in" "quotes". I know that's more keypresses than the + sign, but when maintaining a system as gigantic and complex as the Google search engine, everything is tradeoffs, and that's one that we decided to make.
Oooh maybe they can take out a patent on that idea first...
(Sorry OP, not having a go at you - just getting incredibly frustrated with companies I used to love and respect - like Google and Amazon.)
Google is very concerned about giving users what it thinks they want, rather then what they actually asked for. Sometimes that's great (I love basic stemming), sometimes it fills my results with irrelevant garbage.
"Sambisa" would have found it.
"Sambisa Reserve" would have found it.
"Sambisa Forest Reserve" would have found it.
But my guess is that something attempts to understand keywords and context and when you end with "forest" it looks within the set of forests that are called Sambisa, and actually there isn't a forest called Sambisa, there's a nature reserve called Sambisa, which covers an area within a forest landscape.
Yeah, that's pedantic and Google could do a better job when it attempts to contextualise like that (especially if it's topical), by just doing a second search internally for exact matches and doing a join/merge on the results.
But still... you're going to have the same problem with Open Street Map for the same reason:
http://open.mapquestapi.com/nominatim/v1/search.php?format=j...
http://open.mapquestapi.com/nominatim/v1/search.php?format=j...
http://open.mapquestapi.com/nominatim/v1/search.php?format=j...