# Msg#5 - Software Archetypes - single vs double systems
**URL:** https://discourse.openehr.org/t/msg-5-software-archetypes-single-vs-double-systems/15841
**Category:** Technical (archive)
**Created:** [10 April 2006 17:52 UTC](https://discourse.openehr.org/t/msg-5-software-archetypes-single-vs-double-systems/15841 "2006-04-10T17:52:09Z")
**Posts on this page:** 1
**Page:** 1
### Author:  [@Bill\_Walton](https://discourse.openehr.org/u/Bill_Walton)
#### Post date: [10 April 2006 17:52 UTC](https://discourse.openehr.org/t/msg-5-software-archetypes-single-vs-double-systems/15841/1 "2006-04-10T17:52:09Z")
systems
> Hi Greg,
>
> Greg Woodhouse wrote:
>
> \> What I find most frustrating about discussion of
> \> archetypes is that it is so often vague and intuitive
> \> in nature, making it rather hard to decipher.
>
> I didn't know what level of detail was desired. Also, I'm not an expert
on
> archetypes and, as you'll see below, have no intention of putting myself
> forward as such. Just thought I'd provide what information I could. I
> didn't mean to frustrate, nor to offend. Sorry if I did.
>
> \>
> \> \> 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.
> \
> \> \> Archetypes (which I believe do not depend on an RDBMS
> \> \> implementation) provide a similar capability, but take it to the
domain
> level.
> \>
> \> By domain do you mean application domain?
>
> Not sure exactly what you mean by "application." It may be too
low-level.
> I think of 'domain' as a place where we can, in general, use the same
words
> without having to worry about being misunderstood. So, domain as in
> "domain-specific set of concepts" like medicine or aerospace. Weight, for
> example, is a fairly unambiguous term in medicine, requiring at most I'd
> think, a qualifier for unit of measure. That's because there's an
implicit
> assumption: the domain is "medicine as practiced on the planet Earth."
For
> aerospace folks, however, you might need to provide additional information
> about mass and gravitational field to get to a similar level of (lack of)
> ambiguity.
>
> \
>
> \> \>
> \> \> 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.
> \>
> \> But what does this mean?
>
> As suggested by your sig, I'll forward your email to the experts and get
> back to you with their response(s).
>
> Best regards,
> Bill
>
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