[Data-modeling] Inheritance, subsumption and co-typing

[John Bäckstrand]

Firstly, I am fairly new to freebase so may make stupid assumptions.

I see references to "co-typing" from time to time, I assume this means the
"include type" functionality. What I can see, this is a "hint" and we are
free to remove any types from the "parent", but the link is still there in
the form of /freebase/type_hints/included_types<http://www.freebase.com/tools/explore/freebase/type_hints/included_types>.
This is all fine, because the structure is still there to be
machine-parsable, although this has to be viewed as quite weaker than a more
"normal" hierarchy, because, say, the substitution principle will not hold
for "subclasses".

On the other hand I also see properties with the name "Specialization of",
see /people/profession for an example. This "isa" has absolutely (as far as
I can see) no semantics attached to it, and for a application to be able to
use this information we would need to manually add these properties to a
list of "is-a" equivalents. Shouldn't co-typing (somehow) be used here
instead?

I am guessing this a ease-of-use thing, but I at the same time think this
will severely lower the value of the data that freebase produces. I really
just think (quite possibly because I am a developer) that subsumption should
have a much more high-profile status in Freebase.

-- 
John Bäckstrand
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