Re: [Hardhats-members] Software Archetypes - single vs double systems

[Bill Walton]

Title: Software Archetypes - single vs double systems

Hi Lorie,   Archetypes provide a capability that's very familiar to programmers, but take it to the next level.  At the most basic level, it's about decoupling.  An RDBMS shields programs from the need to know about the underlying structure of the data.  A program needs only know about the db schema.  Views provide another level of abstraction, shielding programs from changes in the schema.  Archetypes (which I believe do not depend on an RDBMS implementation) provide a similar capability, but take it to the domain level.    When working with an archetype-enabled system, programs / programmers work directly with domain concepts like blood pressure or height or weight.  The underlying data is stored / accessed through the archetype.  A trivial example of the benefits would be lbs. vs. kgs..  In an archetype-enabled system, the program has no knowledge of the unit-of-weight measure used to store the data.  Programs access the data store with statements like (no representation made re: syntax) store_weight(220, lbs) and patient_weight = retrieve_weight(patient_id, kgs).   You might want to take a look at http://oceaninformatics.biz/archetypes/MindMap/ArchetypeMap.html for a better, high-level understanding of the above.  This, and a good deal of the related stuff, will be migrated shortly to the openEHR site.   Be happy to provide / get you more in-depth info if desired.   hth,       ----- Original Message ----- From: Lorie Obal To: hardhats-members@lists.sourceforge.net Sent: 2006-04-10 12:12 AM Subject: [Hardhats-members] Software Archetypes - single vs double systems Can anyone clarify/comment on the architecture principles called "archetypes" and "two-level" methodologies used in the openEHR project and openVistA? See: http://www.openehr.org/publications/archetypes/archetypes_beale_oopsla_2002.pdf The openEHR docs imply that this is a significant departure from previous methodologies. I'm trying to compare/contrast this with vistA in a comparison framework. Any enlightenment appreciated. More info on openEHR & archetypes can be found at: http://www.openehr.org/publications/archetypes/t_archetypes.htm -Lorie