Re: [protege-user] [EXT] Modeling Beliefs in OWL?

Michael,

I am curious about your first approach. How do you adjudicate what individuals are members of class Fact? I hardly need point out the practical difficulties in this day and age. And for that matter, what does it mean for an individual to be a member of class Fact? Especially in the context of your Belief class. If f is a Fact, b is a Belief, and b hasFact f, then what’s the point of calling something a belief if f is accepted to be truth?

On reflection, it seems to me that a member of class Fact is, in your interpretation, something that someone believes to be a fact, independent of whether or not it actually is a fact. Is that correct? If so, “Fact” is kind of a misleading name.

The approach may get you into trouble if you try reasoning. I can see a knowledge graph simultaneously containing the following two beliefs:


  1.  Belief 1: Person 1 thinks the average global temperature has risen 1.5° since 1990.
  2.  Belief 2: Person 2 thinks the average global temperature has risen 0.5° since 1990.

To express this according to your approach, you’re going to have pairs of triples independent of the beliefs:


  1.  Fact 1: The average global temperature has risen 1.5° since 1990.
  2.  Fact 2: The average global temperature has risen 0.5° since 1990.

Because reasoners don’t know about your Belief class, they might choke on something like this. It’s hard to say without a full model. Just something to keep in mind as you proceed.

Steve Wartik


From: protege-user <[email protected]> On Behalf Of Michael DeBellis
Sent: Thursday, January 23, 2025 3:04 PM
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Subject: [EXT] [protege-user] Modeling Beliefs in OWL?

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I'm developing an ontology based on an informal model created by some social scientists to model Climate Obstruction and Green Washing. I'm starting with the Gist upper model (but to the extent I understand Gist, I think the following question is  bit more theoretical than what they typically model).

One thing I want to model is beliefs. The problem of course is that since Gist is logical it can't handle axioms that contradict each other and different people believe contradictory things  I've thought of two ways to do it and I'm interested in any feedback people have.

Also, while the eventual knowledge graph will be large (millions of triples at least) the size won't come from beliefs. E.g., I'm not going to need to model thousands of different belief systems. I'll be using individual people as examples and perhaps also groups of people (e.g., the goal of an Exxon PR program is to convince the AmericanConsumer that decreased use of fossil fuel will be bad for the economy). Both Person and Organization are subclasses of Agent and Agent is the domain for believes.

Approach 1). Reified triples. Create a class called Fact. Create object properties hasSubject, hasPredicate, hasObject, where each property's domain is Fact and the range is undefined. Then a Class called Belief with an object property hasFact. A belief consists of one or more facts. So to model Michael thinks Cat1 is on Mat1 create a Fact (Cat1OnMat1) with subject = Cat1, Predicate = isOn and object = Mat1. Make a belief object that consists of this fact Cat1OnMat1Belief and an object property believes and the triple Michael believes Cat1OnMat1Belief. You can assert a Fact is true with a simple Python function or even just a sparql query that gets the triple values and asserts them.

Issues: Have to pun all the values for hasPredicate since those need to be properties. I've had bad experiences when using lots of puns. Honestly, I'm not sure if the problems are from AllegroGraph, Protege or using them together (which I do all the time without problems except when I have lots of puns). I've never spent enough time to figure out what the specific problem(s) are because I found whatever was going wrong I could make it go away by using annotation properties and no puns...  actually another option would be to make hasPredicate an annotation rather than object property.

Approach 2): Use named graphs and only do reasoning within each graph. This seems simpler. So for each Agent's beliefs we would just have a named graph called MichaelBeliefs, AlansBeliefs, etc.

Issues: How to model the connection between an Agent and their Beliefs. Since I don't think OWL understands what a named graph is because its an RDF concept not a logical concept. I think I could create an annotation property that points from the Agent to each named graph.

I was leaning toward 1 which I've done before (on a very small scale) but after talking to a colleague I'm leaning toward 2.

Interested in any critique, feedback, other ideas and/or pointers to relevant papers.

Cheers,
Michael
https://www.michaeldebellis.com/blog

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