Hi Diego, On 26/06/2014 09:16, Diego Bosc? wrote: > Well, I would say that deciding what's in and what's out of the > reference model can be tricky sometimes. If we assume that clinical > knowledge evolves (one of the basis of dual model approach) isn't safe > to say that the less clinical knowledge we put in the reference model > the better?
the problem with this dictum is that it doesn't work as an Occam's razor, which is what you need - i.e. objective criteria for making the decision. The criterion I developed in 2000 or so, to determine what should be in an RM underpinning archetypes was: * the RM should include only domain-invariant semantics i.e. semantics that are widely agreed to be the same across all parts of the chosen domain So for example, we (probably) all agree that a type like DV_QUANTITY / Quantity / PQ should be in the reference model, with the ability to represent at least a Real value + units - because it's a standard concept across the whole health data domain. Do we agree that an EHR 'Entry' is a domain-invariant concept for the domain of say EHRs? It seems to be the case, even if less easily definable what one is, since you find something like it in all EHR models I have seen (including proprietary ones). Are the openEHR concepts Observation, Evaluation, Instruction, Action, AdminEntry domain invariant in the EHR space? I think it can be argued that these concepts are standard not only in medicine but in engineering in general (where the concept of 'maintenance' of systems appears). People involved in building 13606 (I was one of them) on the other hand will differ. That's because what 13606 s trying to do is different - it's not trying to be a model of something based on principle, it's trying to be a model of a consensus view of how heterogeneous health data could be converted into a neutral format for sharing, without losing original semantics. Anyway, in the years since the first archetypes, other people have thought up the 'reference archetype' notion, and ADL /AOM have been greatly improved, in ways that would support that concept. I think we are still working out where this ends. Maybe a modern version of the criterion above will be fractally spread out over layers of RM / archetypes, in a new future where every layer is some kind of programming language whose artefacts act as inputs into the virtual machine represented by the layers below. It will be very interesting to see if new/better principles emerge to say what should go in (or not) to the RM. But one thing I know is: the terms 'less', 'more', 'too much' etc are not useful. - thomas -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/pipermail/openehr-clinical_lists.openehr.org/attachments/20140626/a4eabc12/attachment.html>