On 14/06/2013 08:56, Gerard Freriks wrote: > Hi, > > While we are at it. > > -1- > Why do we need a TDD? > Isn't a Template just a Composition archetype with Sections archetypes > and ENTRY archetypes and Cluster archetypes and Element archetypes > plus data types.
that's what a template is; but a TDD (Template Data Document) is something different. It's not an XML instance of the canonical (i.e. RM) information model XSD, it's an instance of a transform of that, called a TDS (Template Data Schema). A TDS is something like a 'green CDA' schema but /generated /from the AOM template structure. The tag set is a mixture of standard RM attribute names (like 'start_time', 'events', etc), and for the data attributes, names derived from the archetype node ids, i.e. things like 'serum_sodium', or 'total_cholesterol'. The result is an XSD whose tagset consists of basic openEHR context attributes (always the same) and template specific data attribute names. There is therefore one TDS per template - each TDS is its own schema. A TDD is an XML document instance of a TDS. > In addition as many possible degrees of freedom need to be constrained > so as to reflect the agreement between the two exchanging actors. > In all aspects they rare nothing but an archetype in my part of the world. > The peculiar thing about templates is that they are for prime time > actual use/deployment. that's true, but not only that - you need templates to define a data set of any kind. Except in some coincidental cases (like some labs), archetypes don't on their own define useful or complete data-sets. So if a government wants to mandate a discharge summary or e-referral document, they need to define a template to do that, made up of specifically chosen attributes from a set of chosen archetypes. > > -2- > Transformations: > The Template (archetype) has node names changed in places (and > therefor their meaning). At a technical level, the 'meaning' of each node can't be changed from the archetype - and that is the meaning that is computed with. I agree that in some cases, the clinical meaning may be different, but it should always be refined, not arbitrarily different. ADL/AOM 1.5 addresses this properly and makes all template refinements regular and computable. > They are more complex in places (because new branches) have been > added, less complex in places (because branches are not used), more > constrained in places than the pure parent archetype. Currently, no new data at all can be added in an opernEHR template, and no new branches. The only 'new' thing that can be added is clones of existing archetype nodes to account for specific multiplicities required by that data set. > > To write generic transformations is not trivial, I expect. > If possible at all. For TDD -> canonical openEHR (and this would be the same for 13606, CIMI etc) it's not completely trivial, but it's not hard - transformers doing this have been in production for some years how. I don't know if anyone has written a canonical -> TDD transformer, and I am not even that clear on what the need would be, but (see my other post), it would be nearly trivial, assuming that a reasonable TDS was designated as the default target. - thomas -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/pipermail/openehr-technical_lists.openehr.org/attachments/20130614/4658baa5/attachment.html>
