[Data-modeling] Types for subjects

[Jeff Prucher]

<http://www.freebase.com/view/guid/9202a8c04000641f800000000b912218>

This is a thread in which it is proposed that we collapse all the various
media subject types (book subject, film subject, etc.) into one big (new)
Media Subject type.  Functionally, this would result in one type with many
properties, rather than many types with one property each.

The main advantage I can see to this is that users wouldn't have to add new
types if they wanted to indicate that a topic was a subject of a type it
didn't already have (that is, if you wanted to say that a particular radio
program had a subject of, say, "Porcupines", but the Porcupine topic was
only the subject of a book currently, you wouldn't have to add the type
"Radio Subject" -- you could just fill in the property).

A minor advantage _might_ be that people creating types in bases would have
a type they could all reference if they had a new type that needed a subject
property. Although this also has the disadvantage that these properties
would not be reciprocated, whereas if the user created a new "foo subject"
type, it would be.

This would also be a fairly major change, since we'd be nuking a lot of
types, which would potentially break all kinds of things (we could keep the
old property keys, but I'm not sure about the type keys). It also has
implications for other places where similar patterns exist (media genres and
ficitional characters are two that come to mind).

What do you think about this? 

Jeff