- From: Michel_Dumontier <Michel_Dumontier@carleton.ca>
- Date: Sat, 11 Sep 2010 11:31:55 -0400
- To: Lee Feigenbaum <lee@thefigtrees.net>, Michel_Dumontier <Michel_Dumontier@carleton.ca>
- CC: "Eric Prud'hommeaux" <eric@w3.org>, Chimezie Ogbuji <ogbujic@ccf.org>, "public-semweb-lifesci@w3.org" <public-semweb-lifesci@w3.org>
Hi Lee! > -----Original Message----- > From: Lee Feigenbaum [mailto:figtree@gmail.com] On Behalf Of Lee > Feigenbaum > Sent: Saturday, September 11, 2010 2:54 AM > To: Michel_Dumontier > Cc: Eric Prud'hommeaux; Chimezie Ogbuji; public-semweb-lifesci@w3.org > Subject: Re: [TMO] patient record normalization > > On 9/11/2010 2:04 AM, Michel_Dumontier wrote: > >>> It's not a restriction on the predicates - it's a restriction on > >> instances of a certain class - like that of blood pressure > >> measurements. Checking consistency would tell you whether your data > >> conforms to the specification described by the ontology document. > >> > >> Right, but tells whom, and when? including :measuredInUnits > advertises > >> a flexibility which you do not intend to honor. > > > > The predicate would only advertise that the domain would be a > quantity and the range a unit. > > Speaking as someone just browsing this discussion (so take my comments > for what they're worth, which isn't much), I'd tend to agree with Eric > here. If I (as a human) saw this in an ontology, I'd expect that I can > freely mix and match units in my data and that any software processing > the data will cope with it or raise a reasonable error. You are most certainly able use a variety of units - but if an ontology specifies the unit, a a dataset imports the ontology, then a valid dataset would conform to this specification. > >> If I dereference > >> :systolicMPa, I learn that the units are exactly MPa. If I > dereference > >> muo:numericalValue and muo:measuredUnits, I learn that I can use any > >> units (misleading). > > > > It isn't misleading, it's exactly as advertised. > > Would you expect my above assumption to be accurate? It sounded from > some other messages in the thread that there's a thought that even with > the "generic" approach that systems would in general handle data in > homogeneous units? The requirement here is that any and all units can be specified using the relation, but an ontology can restrict the number, *kinds* of units, or specific units applicable. > >> If I wade through the OWL for TMO, I learn that > >> there's a restriction for say: > >> > >> Class: tmo:BloodSystolicPressureReading EquivalentTo: > >> (:value exactly 1) > >> and (:measuredInUnits exactly u:mmHg) > >> > > and (:measureInUnits only u:mmHg) > > > >> which, if I think hard, tells me that I must normalize my data, but > >> this is pretty far from follow-your-nose semantics. > > > > There's no thinking required - the semantics are clearly spelled out > in the axioms. Instances of this class refer to mmHg as the unit. Any > instance that refers to a different unit is not a member of this class. > > There's no thinking required if you have an OWL reasoner as an integral > part of your tool chain. I think, given that the TMO *is* an OWL2 ontology, that use of the toolchain *is* a requirement. > Otherwise, there is thinking required. And > even > if you have an OWL reasoner in your tool chain, you'd probably have to > be doing something clever with integrity constraints a la Clark & > Parsia > to catch errors this way, rather than just to end up asserting bogus > data. No, I don't believe that is the case. m. > Again, apologies if my comments are off-base as I'm mainly just passing > through here! > > Lee > > >> I think I have described why authoring is less fault-prone if the > >> normalized date in TMO uses precise predicates. Do you have other > use > >> cases which override that one? > > > > The counter argument to using a specialized predicate is that > > 1) we cannot describe a unit > > 2) there is a proliferation of relations as there are countless > quantities multiplied by each of their respective units. > > 3) relations can only be weakly described (they do not have the class > constructors available to describe them) > > 4) requires one to query the labels instead of the semantics to find > the appropriate relation. > > 5) requires one to parse the label for the intended unit. > > > > It's a shortcut that makes linked data prettier, but weakens formal > knowledge representation. > > > > m. > > > > > >
Received on Saturday, 11 September 2010 15:32:27 UTC