RE: [TMO] patient record normalization

On Sun, 2010-09-12 at 17:04 -0400, Eric Prud'hommeaux wrote:
> [ . . . ] Offering people a units knob which they are
> forbidden turn is an invitation for well-intentioned invalid data.

I don't think that's correct.  If I as an RDF author saw the following
example:

>> :x :has-attribute
> >   [ a :systolic-blood-pressure;  :has-value 120; :has-unit unit:mPa ]
> >   [ a :diastolic-blood-pressure; :has-value 80; :has-unit unit:mPa ]

I may *initially* think "Oh, I wonder what other units I can use", but
then I would *look* at the ontology to see what other units are
supported, and I would find that the only supported units are mPa.  I
would *never* just blindly make up a term like unit:mmHg and hope that
it is supported, and I don't think others would either.

I think the basic argument for single-unit predicates comes down to
simplicity, as it is decidedly less to write and less to query, and
simplicity *itself* helps to reduce errors:

> > > :X :bloodPressure
> > >   [ :systolicMPa 120 ;
> > >     :diastolicMPa 80 ] .

However, I also think it is important that software be able to
automatically know the units without hard coding, so that it can display
them (for example).  Are you saying that the TMO ontology would also
have an assertion like the following?

  trans:systolicMPa :has-unit unit:mPa .

If so, that need would also be met by the single-units approach.

Conceptually the single-units approach is factoring out the units from
the data, rather than having the same units specified many times across
many data measurements:

>> :x1 :has-attribute 
> >   [ a :systolic-blood-pressure;  :has-value 120; :has-unit unit:mPa ]
>> :x2 :has-attribute 
> >   [ a :systolic-blood-pressure;  :has-value 132; :has-unit unit:mPa ]
>> :x3 :has-attribute 
> >   [ a :systolic-blood-pressure;  :has-value 126; :has-unit unit:mPa ]

Factoring out repeated information is generally a good thing to do, as
it makes descriptions less verbose and (usually) easier to understand
and less error prone.


-- 
David Booth, Ph.D.
Cleveland Clinic (contractor)
http://dbooth.org/

Opinions expressed herein are those of the author and do not necessarily
reflect those of Cleveland Clinic.

Received on Monday, 13 September 2010 22:30:48 UTC