Re: Typing: was Re: DBpedia as possible project

Hi Andrew,

[Inheritance]
> Pass 1 of identifying whether thing T could be an X is whether they
> have the designated properties or not.  Pass 2 of identifying
> whether thing T could be an X is whether those properties' values
> are within the set of acceptable things that I think identify an X.
[...]
> Map A defines a thing of type X and it has properties {a, b, c}

> Map B defines a thing of type Y and it has properties {a, b, d, e, f}

> If I want to merge map A and map B based on things I know about the
> maps (magic), I might be able to say that the thing in map A is a
> "person" and the thing in map B is an "astronaut".  Using my out of
[...]

That's all cool and I agree with you and I agree with the whole
content of your (interesting) e-mail.

And it's also okay to use type-instance relationships to indicate the
profession of a person (personA isa astronaut). That this should be
better modelled as an association where a person plays the role
"astronaut" is a bit nitpicking. If it fits, someone may define:

   bob-the-builder isa construction-worker.

No problem at all. But could be a problem if "construction worker" is
defined as

   construction-worker ako person.

Anyway, as others have stated, there is no absolute truth and each
topic map is context-dependent/domain-specific, so the "Bob the
Builder" statement is valid in several contexts and false in some
other contexts.

Using type-instance relationships more carefully may generate less
false positives. And using type-instance relationships for facts which
don't change (or unlikely change) may make topic maps more robust
(i.e. time independent) or gain a bigger audience which agrees with
the statements made in the topic map.

Best regards,
Lars
-- 
Semagia 
<http://www.semagia.com>

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