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Re: dwbp-ISSUE-134 (BernadetteLoscio): About Formats, schemas, vocabularies and data models [Best practices document(s)]

From: Bernadette Farias Lóscio <bfl@cin.ufpe.br>
Date: Thu, 12 Feb 2015 11:52:10 -0300
Message-ID: <CANx1Pzwm6qcE0t_EQcPkKxV6UyjZGxVdTO-q=NY=V9Ngv2sjNg@mail.gmail.com>
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: "public-dwbp-wg@w3.org" <public-dwbp-wg@w3.org>
Hi Antoine,

I agree with you that schema and vocabulary are defined in the same place.
A schema defined in XML Schema, a relational database schema or an ontology
define both the structure of data and the vocabulary.

Maybe, its better to say that the schema defines both the structure used to
validate the data together with the vocabulary, i.e, the set of terms used
to specify this structure. Is it ok for you?

cheers,
Bernadette



2015-02-09 18:34 GMT-03:00 Antoine Isaac <aisaac@few.vu.nl>:

> Hi Bernadette,
>
> Thanks!
>
> I'm afraid it's still not clear. In Semantic Web parliance, both what you
> call the schema and the vocabulary would be defined in the same place - an
> ontology. I have the feeling that in other technologies that would be the
> same: in XML schema the terms would be introduced and given a definition
> (and a role in the data structure) in an XSD file, wouldn't they?
>
> Antoine
>
> On 2/6/15 5:38 PM, Bernadette Farias Lóscio wrote:
>
>> Hi Antoine,
>>
>> I'm sorry, it was my mistake: Person is part of the vocabulary.
>>
>> Person(name, age, sex, id) defines the schema of the relation, where
>> Person is the name of the relation and (name, age and sex) are attributes
>> of Person.
>>
>> person, name, age, sex, id are terms that compose the vocabulary.
>>
>> cheers,
>> Bernadette
>>
>>
>>
>>
>> 2015-02-06 11:40 GMT-03:00 Antoine Isaac <aisaac@few.vu.nl <mailto:
>> aisaac@few.vu.nl>>:
>>
>>
>>         - the structure of the data should be referred to as the data
>> schema
>>         - the collection of terms used in the schema to describe how to
>>         interpret data values should be refered to as the vocabulary
>>
>>
>>         Person(name, age, sex, id) --> this is the schema
>>         terms name, age, sex and id --> this is the vocabulary
>>
>>
>>
>>     I am sorry but I don't understand the proposal! Is the definition
>> 'Person' part of the schema but not in the vocabulary? The definition of
>> 'name' is in the vocabulary and not in the schema?
>>
>>     Antoine
>>
>>
>>     On 2/3/15 5:02 PM, Bernadette Farias Lóscio wrote:
>>
>>         Hi all,
>>
>>         I'd like to discuss with you the difference between vocabulary,
>> data
>>         schema, data model and data format. João Paulo started this
>> discussion
>>         earlier in this message:
>>         https://lists.w3.org/Archives/__Public/public-dwbp-wg/
>> 2015Jan/__0195.html <https://lists.w3.org/Archives/Public/public-dwbp-
>> wg/2015Jan/0195.html>
>>
>>
>>         It is worth to read the whole message to better understand the
>>         definitions. In the following, I show just parts of the message
>> with
>>         some definitions:
>>         -------------------------
>>         - About data representation and data format
>>
>>         "By "data representation" we mean any convention for the
>> arrangement of
>>         symbols in such a way as to enable information to be encoded by a
>> data
>>         producer and later decoded by data consumers.
>>
>>         A particular convention for data representation is often referred
>> to as a
>>         "data format"."
>>
>>         ....
>>
>>         - About schemas
>>
>>         For example, an XML-based format can be
>>         specified with a "schema document" in the XML Schema Definition
>> language,
>>         enabling XML documents to be checked for conformance to the
>> format defined
>>         in the schema document [XML-SCHEMA].
>>
>>         "schemas" are often used as a means to anchor natural language
>>         descriptions to guide humans in the interpretation of data
>> produced using
>>         the format. Often, labels are used in these schemas to convey
>> intuitive
>>         meaning and guide interpretation, in which case these labels
>> serve the role
>>         of "terms" in communication. The collection of terms as used in
>> the schema
>>         is then referred to as a "vocabulary".
>>
>>         ------------------------------
>>
>>         The notion of schema presented above is similar to the one of
>>         relational schema in the database world. A relational database
>> schema
>>         describes the set of relation schemas of a given database. A
>> relation
>>         schema is composed by the name of the relation together with its
>>         attributes. This specifies how to interpret instances of a given
>>         relation (or table). In the database world, a data model consists
>> of a
>>         set of constructs to build databases. For example, in the
>> relational
>>         model, databases are represented as a collection of relations (or
>>         tables).
>>
>>         IMO vocabularies may be used to describe data schemas even when
>> the
>>         RDF model is not being used. Vocabularies should be used to help
>> tasks
>>         like data integration and to improve data interoperability.
>>
>>         In this case, I suggest:
>>
>>         - the structure of the data should be referred to as the data
>> schema
>>         - the collection of terms used in the schema to describe how to
>>         interpret data values should be refered to as the vocabulary
>>         - the abstract syntax to define schemas should be referred to as
>> data model
>>
>>         Example  (relational schema defined according to the relational
>> data model):
>>
>>         Person(name, age, sex, id) --> this is the schema
>>         terms name, age, sex and id --> this is the vocabulary
>>
>>         cheers,
>>         Bernadette
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>         2015-01-22 13:46 GMT-03:00 Data on the Web Best Practices Working
>>         Group Issue Tracker <sysbot+tracker@w3.org <mailto:
>> sysbot%2Btracker@w3.org>>:
>>
>>             dwbp-ISSUE-134 (BernadetteLoscio): About Formats, schemas,
>> vocabularies and data models  [Best practices document(s)]
>>
>>             http://www.w3.org/2013/dwbp/__track/issues/134 <
>> http://www.w3.org/2013/dwbp/track/issues/134>
>>
>>             Raised by: Joao Paulo Almeida
>>             On product: Best practices document(s)
>>
>>             The group needs to settle on some concepts (and ultimately
>> terms) that should help us to structure our discussions,  give us a basis
>> to communicate and help our audience to understand us.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> Bernadette Farias Lóscio
>> Centro de Informática
>> Universidade Federal de Pernambuco - UFPE, Brazil
>> ------------------------------------------------------------
>> ----------------
>>
>
>


-- 
Bernadette Farias Lóscio
Centro de Informática
Universidade Federal de Pernambuco - UFPE, Brazil
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Received on Thursday, 12 February 2015 14:53:08 UTC

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