RE: Propose an HL7 work group on RDF for Semantic Interoperability?

Hi Rafael,

On 05/13/2014 05:29 PM, Richards, Rafael M. wrote:
 > What problem is RDF solving that HL7 is not?

Great question!  RDF complements and supports information 
standardization activities.

The problem is that each information representation standard becomes its 
own interoperability silo.  Each one attempts to achieve 
interoperability by expecting the world to conform *its* data format or 
*its* data model or *its* vocabulary.  If the entire world did, then 
indeed the interoperability problem would be solved.  But for many 
reasons, the entire world does not -- and never will -- including:

  - Political or business reasons.  For example, proprietary information 
representations are still a sad fact of life in healthcare.

  - Systems cannot all suddenly change at once, in one synchronous big 
bang, to use a single new standard.  At least until we reach nirvana, 
when all healthcare systems speak the same language with the same 
meanings, we MUST accommodate a diversity of standards and versions.

  - The world is continually changing, with new medical techniques and 
technology continually requiring new concepts that must be standardized.

  - An individual standard cannot cover all use cases -- at least not 
well -- or the standardization committee would never finish its work!
Each standard typically tries to address a particular range of use 
cases, excluding or poorly addressing others.  But there is no end to 
the use cases, because healthcare connects with everything else.

  - Different use cases require different kinds and granularities of 
information.  A blood pressure measurement that fails to indicate the 
patient's position (standing or sitting) may be good enough for some 
purposes but inadequate for others.  When an automated blood pressure 
machine is used, details about its make and model may be irrelevant to 
most use cases but may be critical for a few that are looking for subtle 
trends and thus may be sensitive to systemic differences between models. 
  Fine grained information is great when it is needed, but harmful when 
it is not needed, because it adds complexity.

  - The data formats, models and terms chosen in a particular standard 
may be distasteful or hard for some parties to use.  The designers of a 
particular standard may not have always made the best choices, though 
the notion of "best" is very subjective and changes over time.

For these fundamental reasons (and probably several others too), the end 
result of standardization efforts is often this:
http://xkcd.com/927/

This is NOT to disparage any particular standards effort, nor is it to 
imply that standardization is pointless or unnecessary.  Standardization 
*is* needed.  But at the same time it is important to recognize the 
inherent challenges and limitations of standardization.

So, returning to your question of what problem RDF solves that HL7 does 
not, RDF addresses this standardization problem at its root, by:

  - being completely independent of data format, data model and domain 
vocabulary.  RDF allows the process of standardizing data models and 
vocabularies to be *decoupled* from the underlying semantic 
representation.  Standardization can continue in parallel.

  - providing a common semantic foundation that can span across all 
healthcare information representation standards.  RDF allows multiple 
standards to be mixed and matched.  This will also make standardization 
much easier, because data models can be standardized in much smaller 
pieces.  Divide and conquer!

  - providing a common abstract information representation that: (a) can 
losslessly represent any structured information; and (b) can act as an 
abstract lingua franca for defining and sharing model transformations, 
via ontologies and rules, for use when they are needed.   And model 
transformations will *always* be needed to some extent . . . at least 
until we reach nirvana.  ;)  These model transformations used to be done 
inside proprietary black box integration engines.  But RDF allows them 
to be represented explicitly and visibly, enabling them to be shared and 
standardized.

In short, RDF does not enable semantic interoperability by itself, but 
it facilitates the process of achieving semantic interoperability, both 
by supporting and complementing standardization efforts and by 
facilitating model transformations.

Sorry for such a long answer, but I hope this helps.  It was a great 
question.

David

Received on Wednesday, 14 May 2014 22:10:11 UTC