Hi Marco,

There are a number of ways to work with sets, but I don't think I'd approach this problem from that point of view. Rather, I would start by thinking about what my domain instances are, what their properties are, and what kinds of questions I want to be able to ask based on the representation. I'll sketch this out a bit, though the fact that I name an object or property doesn't mean that you have to supply it (remember OWL is open-world) - still listing these make the ontology makes your intentions clearer and the ontology easier to work with by others.

The heading in each of these is a class, of which you would make one or more instances to represent your results.
The indented names are properties on instances of that class.

An expression technology:
   Vendor:
   Product: e.g. array name
   Name of spots on the array
Mappings: (maps of spot to gene - you might use e.g. affymetrix, or you might compute your own)

ExpressionTechnologyMap
  SpotMapping: (each value a spot mapping)

Spot mapping:
  SpotID:
  GeneID:

An expression profile experiment (call yours exp0)
   When done:
   Who did it:
   What technology was used: (an expression technology)
   Sample: (a sample)
   Treatment: ...
   Levels: A bunch of pairs of spot name, intensity

Spot intensity
  SpotID:
  Intensity:

A  computation of which spots/genes are "expressed" (call yours c1)
   Name of the method : e.g. mas5 above threshold
   Parameter of the method: e.g. the threshold
   Experiment: exp0
   Spot Expressed: spots that were over threshold
   Gene Computed As Expressed: genes that were over threshold

And maybe:

Conclusion
   What was concluded:
   By who:
   Based on: c1

All of what you enter for your experiment are instances (so there are no issues of OWL Full)

Now, The gene set you wanted can be expressed as a class:

Let's define an inverse property of "GeneComputedAsExpressed", call it "GeneExpressedAccordingTo"

Class(Set1 partial restriction(GeneExpressedAccordingTo hasValue(c1))

Instances of Set1 will be those genes. You may or may not want to actually define this class. However I don't think that you need to add any properties to it. Everything you would want to say probably wants to be said on one of the instances - the experiment, the computation, the conclusion, etc.

Let me know if this helps/hurts - glad to discuss this some more

-Alan




2)

On Sep 8, 2006, at 11:58 AM, Marco Brandizi wrote:


Hi all,

sorry for the possible triviality of my questions, or the messed-up mind
I am possibly showing...

I am trying to model the grouping of individuals into sets. In my
application domain, the gene expression, people put together, let's say
genes, associating a meaning to the sets.

For instance:

Set1 := { gene1, gene2, gene3 }

is the set of genes that are expressed in experiment0

(genei and exp0 are OWL individuals)


I am understanding that this may be formalized in OWL by:

- declaring Set1 as owl:subClassOf Gene
- using oneOf to declare the membership of g1,2,3
(or simpler: (g1 type Set1), (g2 type Set1), etc. )
- using hasValue with expressed and exp0

(right?)

Now, I am trying to build an application which is like a semantic wiki.

Hence users have a quite direct contact with the underline ontology, and
they can write, with a simplified syntax, statements about a subject
they are describing (subject-centric approach).

Commiting to the very formal formalism of OWL looks a bit too much...
formal... ;-) and hard to be handled with a semantic wiki-like application.

Another problem is that the set could have properties on its own, for
instance:

Set1 hasAuthor Jhon

meaning that John is defining it. But hasAuthor is typically used for
individuals, and I wouldn't like to fall in OWL-Full, by making an OWL
reasoner to interpret Set1 both as an individual and a class.

Aren't there more informal (although less precise) methods to model
sets, or list of individuals?

An approach could be modeling some sort of set-theory over individuals:

set1 isA GeneSet
set1 hasMember g1, g2, g3
...

set1 derivesFromUnionOf set2, set3

...

But I am not sure it would be a good approach, or if someone else
already tried that.

Any suggestion?


Thanks in advance for a reply.

Cheers.

--

====================================================================== =========
Marco Brandizi <[EMAIL PROTECTED]>
http://gca.btbs.unimib.it/brandizi




Reply via email to