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Re: PROV-ISSUE-89 (what-entity-attributes): How do we find the attributes of an entity? [Formal Model]

From: Satya Sahoo <satya.sahoo@case.edu>
Date: Thu, 8 Sep 2011 12:16:06 -0400
Message-ID: <CAOMwk6zDnVz8vbPQy4baaKO+56wZxkdZU5ecm7qMUsS-8QWRBA@mail.gmail.com>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Cc: public-prov-wg@w3.org
Hi Luc,
My responses are interleaved:

> "instance" indeed e.g.:  entity(e0, [ type: "File", location:
"/shared/crime.txt", creator: "Alice" ])
ok

> Using the Provenance Abstract Syntax Notation, I could assert two entities
(instances)
> entity(e1,[ company: "Toyota", model: "Corolla"])
> entity(e2,[ company: "Toyota", model: "Corolla", owner="tom"])
The entity we are referring to is an instance of "Toyota Corolla car" and
its identifying attribute is "1a", which distinguishes this instance from
other instances of "Toyota Corolla car". As described in my earlier mail, we
first need to decide what are the "necessary" attributes of an instance and
depending on that we can enumerate them for uniquely "identifying" that
entity.

So,
entity(e1,[ company: "Toyota", model: "Corolla"]) should include attribute
"vehicle identification number" with value "1a".

entity(e2,[ company: "Toyota", model: "Corolla", owner="tom"]) is the same
entity as e1, but with an additional (non-essential?) atribute of ownership.

e1 and e2 can exist, but it should be explicit that e2 is e1 with additional
"necessary" attributes.


> How do I know the attributes of each entity: company/model for e1 and
company/model/owner for e2?
I am not sure I completely understand the query - but we would follow the
attributes/property links associated with both e1 and e2 to retrieve the
appropriate values.

Thanks.

Best,
Satya

On Thu, Sep 8, 2011 at 10:30 AM, Luc Moreau <L.Moreau@ecs.soton.ac.uk>wrote:

> **
> Hi Satya,
>
> Responses interleaved
>
>
> On 09/06/2011 06:26 PM, Satya Sahoo wrote:
>
> Hi Luc,
> To clarify a few points:
> 1. In case of the provenance ontology (formal model), there are two types
> of information resources (entities) - a class of entities (TBox or part of
> ontology schema) and individual entities (ABox or instances of an entity
> class).
>
>  2. There are two types of attributes - (a) attributes necessary for an
> information resource to have to be member of a class of entities
> (intensional definition), and (b) set of attributes associated with a class
> of entities, but they are not necessary for an information resource to be
> member of a class of entities
>
>  Given the above points,
> > The conceptual model defines an entity in terms of an identifier and a
> list of attribute-value pairs.
> Does this identify an "instance" entity or "class" entity?
>
>
> "instance" indeed
>
> e.g.:  entity(e0, [ type: "File", location: "/shared/crime.txt", creator:
> "Alice" ])
>
>
>
>  >  It is indeed crucial for the asserter to identify the attributes that
> have been frozen in a given entity.
> Seems to refer to "instance" entity - for those attributes that form part
> of the intensional definition of the "class" entity.
> For example, a Toyota Corolla Car with vehicle identification number "1a"
> will have "frozen" values of "toyota" and "corolla" for attributes
> "manufacturing company" and "car model name". But, it can have "variable"
> values of "ann" or "tom" for attribute "current owner".
>
>  Using the Provenance Abstract Syntax Notation, I could assert two
> entities (instances)
>
> entity(e1,[ company: "Toyota", model: "Corolla"])
>
> entity(e2,[ company: "Toyota", model: "Corolla", owner="tom"])
>
>
> How do I know the attributes of each entity: company/model for e1
> and company/model/owner for e2?
>
> Cheers,
> Luc
>
>
>
>  With the above description and examples, can you please clarify your
> point again?
>
>  Thanks.
>
>  Best,
> Satya
>
> On Fri, Sep 2, 2011 at 4:52 AM, Provenance Working Group Issue Tracker <
> sysbot+tracker@w3.org> wrote:
>
>>
>> PROV-ISSUE-89 (what-entity-attributes): How do we find the attributes of
>> an entity? [Formal Model]
>>
>> http://www.w3.org/2011/prov/track/issues/89
>>
>> Raised by: Luc Moreau
>> On product: Formal Model
>>
>> The conceptual model defines an entity in terms of an identifier and a
>> list of attribute-value pairs. It is indeed crucial for the asserter to
>> identify the attributes that have been frozen in a given entity.
>>
>> Currently, the ontology does not seem to identify these attributes.
>>
>> To say that these attributes could be found by looking at all the
>> properties for this entity does not work with an open world assumption.
>>
>> What mechanism do we have to identify these attributes?
>>
>>
>>
>>
>>
>>
>
> --
> Professor Luc Moreau
> Electronics and Computer Science   tel:   +44 23 8059 4487
> University of Southampton          fax:   +44 23 8059 2865
> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
> United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
>
>
Received on Thursday, 8 September 2011 16:16:41 GMT

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