[Developers] With attachment, and additional info: Visualization of freebase topics organization

[Alec Flett]

>   - Can the Category hierarchy (that starts on the Data page) be
> ascertained by using MQL queries?
>   
Yep. /freebase/domain_category is the type I believe... but read below
>   - Does each node in this higher level classification have only one
> parent (is it a taxonomy), or should I be thinking more in terms of an
> ontology (nodes in this higher level can have multiple parents, related
> nodes, etc. I'm of course going to study the freebase website, etc. for
> this info, but any input/insights you have would be appreciated."
>
>   
Honestly, I don't think you should rely too much on domain categories.. 
they're merely a set of hints for the freebase.com UI and aren't 
organized in any ontologically rigorous manner. I don't think anyone is 
making any guarantees about domain categories.
> One can navigate from a Domain Category (e.g. Arts & Entertainment) all
> the way down to a topic (e.g. Phil Collins) that exists in its Domain
> Category/Domain/Type hierarchy.  Is it also possible to navigate from
> another Domain Category down to Phil Collins?  I don't see how at this
> point, because the "included types" relationship between Type
> "/people/person" and Type "/film/actor" seems to be only from the bottom
> up.
>
>   
It's /always/ possible to navigate in both directions using 
any_reverse/any_master.. all relationships in the system are 100% 
bidirectional. however...

I think one key thing to understand is that "included types" are not 
part of the schema - they are merely hints that say "when you type 
something as an actor, you should also type them as a person" - this is 
not enforced by MQL in any way and in fact is only implemented in the 
freebase.com UI right now.

Phil Collins himself needs to have all the appropriate type links - i.e. 
he has to be explicitly typed as a person to be considered a person. It 
doesn't get implied or inherited by being a Film Actor. The classic 
example here is Benji the Dog, who may be a film actor but not a person.

So basically I would avoid trying to use included_types when dealing 
with instance data.

So I think your diagram might look something like (turned sideways, in 
ASCII)

Society --domain--> /people --types--> /people/person --instance--> Phil 
Collins

A&E     --domain--> /film   --types--> /film/actor    --instance--> Phil 
Collins

Alec
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freebase.com/pipermail/developers/attachments/20070928/49120fb2/attachment.htm