Re: comments on Editor's Draft of UCR -- motivates links

Peter,


> > > Default behaviour
> > > 
> > >    RIF must specify at the appropriate level of detail the default
> > >    behavior that is expected from a RIF compliant application that
> > >    does not have the capability to process all or part of the rules
> > >    described in a RIF document, or it must provide a way to specify
> > >    such default behavior.
> > > 
> > >    not motivated by Use Case 2.2, Use Case 2.4, Use Case 
> > > 2.5, Use Case
> > >    2.6 
> > 
> > From use case 2.6:
> > 
> > "This use case illustrates how the RIF makes it possible to merge
> > rulesets from diverse sources in diverse formats into one rule-based
> > system, thereby enabling inferences that might otherwise have remained
> > implicit."
> > 
> > This rule-based system may get rules that it can't (completely) 
process
> > and involves important medical decisions so I'd say that default
> > behavior is motivated.
> 
> I still don't see this as part of the use case.  I don't see how the use
> case speaks to partial understanding of rule sets.  On the contrary, I
> would say that this use case speaks to the necessity of *complete*
> processing of rule sets, because otherwise some important rule might no 
be
> processed accurately and someone might die.
> 

I believe the point David is making --- and with which I agree --- is that 
many medical rules are better expressed as default rules than as universal 
rules. For example, in this use case (2.6), the rule 

"If an oral monotherapy at recommended doses of a sulfonylurea or 
biguanide, combined with lifestyle changes, is ineffective, then the 
monotherapy should be replaced by an oral bitherapy."

would be better expressed as a default:

"If an oral monotherapy at recommended doses of a sulfonylurea or 
biguanide, combined with lifestyle changes, is ineffective, then the 
monotherapy should *usually* be replaced by an oral bitherapy."

using whatever means you prefer to express defaults (eg., abnormality 
predicates).  There are, after all, probably exceptions to this rule: 
there many be another class of drugs worth trying as a monotherapy, or the 
patient's particular medical situation may contradict an oral bitherapy 
and may necessitate insulin injections. And one would want to be able to 
specify these exceptions in the rules.

I agree that slightly modifying this use case would better highlight the 
need for defaults, and I'd be happy to make such a modification for the 
next draft.

By the way, use case 2.10 shows a clear need for defaults. That case 
includes the rule: 

"Every movie produced before 1930 is black and white."

Actually, *most* movies were black and white, but some were in color; 
there were different coloring technologies introduced early on, including 
an early version of Technicolor introduced in 1917. Not that I'm a movie 
buff or anything ;) ; the point just is the need for defaults.


> > > OWL data
> > > 
> > >    RIF must cover OWL knowledge bases as data where compatible with
> > >    Phase 1 semantics.
> > > 
> > >    not motivated by Use Case 2.4, Use Case 2.6
> > 
> > While 2.6 doesn't specifically mention OWL, it does mention ontologies
> > as a possible data source. I think parts of SNOMED have been 
translated
> > to OWL, but I'm no expert.
> 
> Sure, but you can write (very, very, very) simple ontologies in just 
RDFS,
> so there is no demonstrated need for OWL.

I believe the point is that  parts of SNOMED have actually been translated 
to OWL, or that there are intentions to do so. If parts of SNOMED are or 
will be in OWL, then the RIF will have to handle OWL in order to use 
SNOMED. Whether or not these ontologies could have been represented in a 
simpler language is irrelevant.


> 
> Note that many of my complaints could be addressed by appropriate
> modification of the use cases.

Absolutely.

Leora