Assistance for new user

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Assistance for new user

Don Rogerson
Hello, I am new to ontologies and to Protege and am hoping someone may have time to indulge what are certainly naive questions.

I have a group of elements I want to be able to classify based partly on size. As an illustration, say you want to include a height attribute for a group of people and to classify those above 2 meters as "Tall" those below 1 meter as "Short" and those in between as "Average"

What I have done is create a Data Property called Height and assert a Height for each individual. Then I have created a class called Tall and set it equivalent to Thing and Height min 2. When I run the reasoner, however, it does not infer that the "Tall" individuals belong to the Tall class. I get no members.

I can get the results I want if I define a set of possible heights as individuals and assign them as Object Properties, but it is not practical to define every possible height. Perhaps I am misunderstanding the usage of the data property?

Don Rogerson
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Re: Assistance for new user

Steve Wartik

Don,

 

What I have done is create a Data Property called Height and assert a Height for each individual. Then I have created a class called Tall and set it equivalent to Thing and Height min 2. When I run the reasoner, however, it does not infer that the "Tall" individuals belong to the Tall class. I get no members.

 

Your phrase “Height min 2” leads me to guess your restriction looks something like the following:

 

 

If so, that’s not what you intend. This restriction says that an individual is a member of class Tall if there are two or more height assertions for the individual. That is, an individual would be “Tall” if it had the two data property assertions:

 

 

What you mean is that there exists a data property assertion involving height whose value is at least 2. In OWL, this is done using facets. The syntax for the restriction on Tall is:

 

 

Does that solve your problem? If not then you may have to send your ontology.

 

Regards,

 

Steve Wartik


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Re: Assistance for new user

Don Rogerson
<base href="x-msg://284/">Steve,

Thank you - This is exactly what I want to do. 

I am learning by modifying the basic family ontogoloy I found with this tutorial: https://wiki.csc.calpoly.edu/OntologyTutorial/wiki/IntroductionToOntologiesWithProtege

Unfortunately it does not cover data properties in much detail (or mention facets at all). Recommendations for a good intermediate-level tutorial would be welcome. 

Don


On Dec 31, 2013, at 2:18 PM, Wartik, Steven P Steve wrote:

Don,
 
What I have done is create a Data Property called Height and assert a Height for each individual. Then I have created a class called Tall and set it equivalent to Thing and Height min 2. When I run the reasoner, however, it does not infer that the "Tall" individuals belong to the Tall class. I get no members.
 
Your phrase “Height min 2” leads me to guess your restriction looks something like the following:
 
<image002.png>
 
If so, that’s not what you intend. This restriction says that an individual is a member of class Tall if there are two or more height assertions for the individual. That is, an individual would be “Tall” if it had the two data property assertions:
 
<image003.png>
 
What you mean is that there exists a data property assertion involving height whose value is at least 2. In OWL, this is done using facets. The syntax for the restriction on Tall is:
 
<image004.png>
 
Does that solve your problem? If not then you may have to send your ontology.
 
Regards,
 
Steve Wartik
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https://mailman.stanford.edu/mailman/listinfo/p4-feedback


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