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Using the RDS/WIP (RDL Façade)
Status of this document: Final Review
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Contents
Abstract
This section shows how to use the RDL Façade, one of several RDS/WIP readers. The RDL Façade can be used both by people browsing for RDS/WIP terminology, and by computer programs during automated data exchanges.
Human Interface
Website: rdl.rdlfacade.org
When you navigate to this site with a web browser, it defaults to a search screen that humans can use to examine the taxonomy of RDS/WIP terminology.
RDL Façade Rules
- Not case-sensitive
- search-string returns all terms containing the full search string
- ^search_string returns terms beginning with the search string
- ^search-string$ returns a single exact match
To Do
In the search box, search for:
- temperature
RDS/WIP will return all terms containing temperature, in groups of twenty.
- TEMPERATURE
RDS/WIP should return the same results since it is not case-sensitive.
- ^temperature
RDS/WIP will return all terms beginning with temperature.
- ^temperature$
RDS/WIP should return only one term, TEMPERATURE.
- After the above search, select the one term, TEMPERATURE
RDL Façade Results Page
General
- RDS/WIP URI - The is the Uniform Resource Identifier (URI) for the term TEMPERATURE. If you enter this text string into your web browser, you will see this page.
- Label - The official designator for this term. Within the database, this designator is unique.
- Description - This helps you know whether or not you have the correct term.
- Entity Type - Think of this as the general category to which TEMPERATURE belongs.
PCA Attributes (POSC/Caesar Attributes)
Some information about this term.
Classification
Aspects of the current term. Next to merely describing the aspects in the description, the terms must also be modelled to make them computer-interpretable. This kind of modelling of aspects is the ontology about the term.
Specialization
The first term shown, ISO 15926-4 SINGLE PROPERTY DIMENSION, is the class that TEMPERATURE is descended from. You can follow downwards to see the full pedigree, or taxonomy. When more than one term is at the same indentation level, it indicates multiple inheritance. For instance ISO 15926-4 INDIVIDUAL CLASS is descended from two classes, ISO 15926-4 CLASS and ISO-IS 15926-2 CLASS OF CLASS.
The diagram you see is drawn upside down compared to most depictions of inheritance. The diagram below is shown in a more conventional manner, with the child at the bottom, and the parent at the top.
Fig 1 - Understanding Specialization
Known Direct Subclasses
All of the terms that have TEMPERATURE as their immediate superclass.
Machine Interface
Website: rdl.rdlfacade.org/data
When you navigate to this site with a web browser, it defaults to the same search screen described above. But when computer programs send it the right kind of queries, this site can validate definitions of terms that are used to exchange data. So for instance, instead of saying something like "Here comes a value for TEMPERATURE", a computer can say something much simpler like, "Here comes a value for the attribute represented by the URI http://rdl.rdlfacade.org/data#R41192093771."
(Now, if you are like the author, you don't find the second statement simpler at all. But that's OK. All it really means is that you, like the author, are not a computer!) The reason the second statement is "simpler" is that although TEMPERATURE is written very definitively (and in capital letters!), the term is still ambiguous. That is, although you can rule out 99.9999...% of the things in the world that have nothing to do with heat and the measurement thereof, there are still a great many things that are related to TEMPERATURE in some way, and which one of them do you mean?
But when you substitute the Uniform Resource Identifier (http://rdl.rdlfacade.org/data#R41192093771), the partner you are exchanging data with can drill down through the taxonomy of the term TEMPERATURE to find out exactly what you mean.
The RDS/WIP is what we call a triple store, which stores data in the form of Subject, Predicate, Object. Automated queries use a language called SPARQL (pronounced sparkle).
To use a SPARQL query, use this site:
Website: http://rdl.rdlfacade.org/data?info=&search=&sparql=
You will see a text input box with some example SPARQL code, which you can execute by clicking on the Get Results button.
To Do
Delete the example code in the text input box and paste in the following code:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dm: <http://dm.rdlfacade.org/data#>
SELECT ?s ?p ?o
WHERE
{ ?s ?p ?o .
?s rdf:type dm:Scale .
}
OFFSET 0
LIMIT 100
This will show the first 100 of over 2000 units of measurements (Entity Data Type 'Scale' in the ISO 15926-2 data model.
To Do
Click on the following code:
You will get a reply back. This is what an automated data exchange program would use to get standard SPARQL XML output which can be taken by the data exchange program and handled internally. If you save the reply as a text file with an XML extension, Internet Explorer will open the file and format it as an XML file you can read.
Attachments
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RDL_Facade01.JPG
(38.2 kB) - added by gordonrachar
14 years ago.
Understanding Specialization
