Christian Heller wrote: >Dear Sam, > > > >> We have been discussing the issue of templates and whether we keep an >>identifier of a template in the data. My concern has been that this ID >>might be seen as an absolute constraint on the data, whereas the precedence >>of constraint must be: >> >> > >knowledge models (reference models as existent in memory) do NOT need >to hold a link to the knowledge template (archetype) they were created >(instantiated) from at all. > >A knowledge model is a clone of a knowledge template. >The template merely delivers the initial values, not more. > > Hi Christian, well, that is one design approach, but it is not the one that we use in openEHR. In openEHR, the archetypes are seen as part of the "ontology of information" (distinct from ontologies of the "real world" like snomed-ct etc). We use them extensively in their own right. We don't repeat all the archetype defnition informatoin in the actual data because a) it would double the size of the data, while making it harder to compute with; b) the persistent form of the data is not necessarily the desired persistence form of the archetypes (in fact, it certainly isn't...) and c) we want to make the data comprehensible to systems and users not using archetypes.
> > >>The data must conform to the reference model >>The data must conform to the archetypes >>The data must be complete >>The template can be invoked to ease data entry. >> >> > >You have to put all constraints into the runtime (reference) model, >so that the model does not have to refer to its original template anymore! > > again, that is a valid desing approach, but we don't use it; we find it is much clearer to have separated data and archetypes. - thomas beale - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
