RE: FW: A Fresh Look Proposal (HL7)

hi dave,



yes, hData does look interesting, reminds me quite a bit of the SOAP
protocol in that it wraps the payload which can be[1]:



"HL7 hData Record Format (HRF) - this specification specifies an abstract
hierarchical organization, packaging, and metadata for individual documents
(referred to as “Section Documents” within the HRF specification). *Section
Documents can be of any type, either XML documents (such as CDA documents,
H7v3 messages, or simplified XML wire formats, etc.) or of other media types
(such as e.g. MS Word documents or DICOM files)*. Also contained in this
specification is the format for specifying the content that goes into an
hData record, which is called the hData Content Profile (HCP) format."

where the Section Documents is the payload where i imagine you see the RDF
document going?

cheers,

michael



[1]
http://www.projecthdata.org/documents/pubs/hdata%20Record%20Format-v19.docx





*From:* public-semweb-lifesci-request@w3.org [mailto:
public-semweb-lifesci-request@w3.org] *On Behalf Of *Hau, Dave (NIH/NCI) [E]
*Sent:* Saturday, September 17, 2011 11:32 AM
*To:* Jim McCusker; conor dowling
*Cc:* public-semweb-lifesci@w3.org
*Subject:* RE: FW: A Fresh Look Proposal (HL7)



Back to "forget the plumbing" and focus on the content, how would you define
a unit of content for a particular purpose (e.g. a blood pressure reading)
in OWL and/or RDF?  This would correspond to an archetype or Detailed
Clinical Model (DCM), and would be a subset of the domain ontology(s).



I also came across the hData effort which seems very promising:



http://www.projecthdata.org



They are proposing a REST mechanism for transport (with some basic HTTP
based security as well), and a generic content format (hData Record Format)
that's primarily XML based currently, but potentially could be adapted to
carry RDF payload.  (The REST mechanism claims conformance to the OMG RLUS
profile, with a semantic signifier linking the data to the information
model.  IMHO this could potentially be adapted to use RDF instead, that's
linked to concepts in an OWL model.)  Is there a REST mechanism to expose
RDF data?



- Dave







*From:* Jim McCusker [mailto:james.mccusker@yale.edu]
*Sent:* Monday, August 22, 2011 9:40 AM
*To:* conor dowling
*Cc:* Hau, Dave (NIH/NCI) [E]; public-semweb-lifesci@w3.org
*Subject:* Re: FW: A Fresh Look Proposal (HL7)



I was just crafting a mail about how our investment in XML technologies
hasn't paid off when this came in. What he said. :-)

On Mon, Aug 22, 2011 at 9:33 AM, conor dowling <conor-dowling@caregraf.com>
wrote:

>> The content matters, the format does not.



should be front and center. Talk of XML that or JSON this, of RDF as XML in
a chain is a distraction - it's just plumbing. There are many tool-chains
and implementors are big boys - they can graze the buffet themselves.



Central to any patient model rework (I hope) would be the interplay of
formal specifications for terminologies like SNOMED along with any patient
data information model. What should go in the terminology concept (the
"object" in RDF terms) - what is left in the model (the "predicate"). Right
now, this interplay is woefully under specified and implementors throw just
about any old concept into "appropriate" slots in RIM (I know this from
doing meaningful use tests:
http://www.caregraf.com/blog/being-allergic-to-allergies,
http://www.caregraf.com/blog/there-once-was-a-strawberry-allergy ) BTW, if
SNOMED is the terminology of choice (for most) then the dance of it and any
RIM-2 should drive much of RIM-2's form.



This is a chance to get away from a fixation on formats/plumbing/"the trucks
for data" and focus on content and in that focus to consider every aspect of
expression, not just the verbs (RIM) or the objects (SNOMED) but both.



Back to "forget the plumbing": if you want to publish a patient's data as an
RDF graph or relational tables or you want a "document" to send on a wire,
if you want to query with a custom protocol or use SPARQL or SQL, you should
be able to and not be seen as an outlier. Each can be reduced to equivalents
in other formats for particular interoperability. The problem right now is
that so much time is spent talking about these containers and working
between them and too little time is given over to what they contain,



Conor



On Mon, Aug 22, 2011 at 6:01 AM, Hau, Dave (NIH/NCI) [E] <haudt@mail.nih.gov>
wrote:

I see what you're saying and I agree.



The appeal of XML (i.e. XML used with an XSD representing model syntactics,
not XML used as a serialization as in RDF/XML) is due in part to:



- XML schema validation API is available on virtually all platforms e.g.
Java, Javascript, Google Web Toolkit, Android etc.

- XML schema validation is relatively lightweight computationally.  Pellet
ICV and similar mechanisms are more complete in their validation with the
model, but much more computationally expensive unless you restrict yourself
to a small subset of OWL which then limits the expressiveness of the
modeling language.

- XML provides a convenient bridge from models such as OWL to relational
databases e.g. via JAXB or Castor to Java objects to Hibernate to any RDB.

- Relational querying and XML manipulation skills are much more plentiful in
the market than SPARQL skills currently.

- Some of the current HL7 artifacts are expressed in XSD format, such as
their datatypes (ISO 21090 ; although there are alternative representations
such as UML, and there is an abstract spec too from HL7).  If we operate
with OWL and RDF exclusively, would need to convert these datatypes into
OWL.



Maybe it'd be worthwhile to get a few of us who are interested in this topic
together, with some of the HL7 folks interested, and have a few calls to
flush this out and maybe write something up?



- Dave









*From:* Jim McCusker [mailto:james.mccusker@yale.edu]
*Sent:* Sunday, August 21, 2011 6:12 PM
*To:* Hau, Dave (NIH/NCI) [E]
*Cc:* public-semweb-lifesci@w3.org
*Subject:* Re: FW: A Fresh Look Proposal (HL7)



I feel I need to cut to the chase with this one: XML schema cannot validate
semantic correctness.



It can validate that XML conforms to a particular schema, but that is
syntactic. The OWL validator is nothing like a schema validator, first it
produces a closure of all statements that can be inferred from the asserted
information. This means that if a secondary ontology is used to describe
some data, and that ontology integrates with the ontology that you're
attempting to validate against, you will get a valid result. An XML schema
can only work with what's in front of it.



Two, there are many different representations of information that go beyond
XML, and it should be possible to validate that information without anything
other than a mechanical, universal translation. For instance, there are a
few mappings of RDF into JSON, including JSON-LD, which looks the most
promising at the moment. Since RDF/XML and JSON-LD both parse to the same
abstract graph, there is a mechanical transformation between them. When
dealing with semantic validity, you want to check the graph that is parsed
from the document, not the document itself.



The content matters, the format does not. For instance, let me define a new
RDF format called RDF/CSV:



First column is the subject. First row is the predicate. All other cell
values are objects. URIs that are relative are relative to the document, as
in RDF/XML.



I can write a parser for that in 1 hour and publish it. It's genuinely
useful, and all you would have to do to read and write it is to use my
parser or write one yourself. I can then use the parser, paired with Pellet
ICV, and validate the information in the file without any additional work
from anyone.



Maybe we need a simplified XML representation for RDF that looks more like
regular XML. But to make a schema for an OWL ontology is too much work for
too little payoff.



Jim

On Sun, Aug 21, 2011 at 5:45 PM, Hau, Dave (NIH/NCI) [E] <haudt@mail.nih.gov>
wrote:

Hi all,



As some of you may have read, HL7 is rethinking their v3 and doing some
brainstorming on what would be a good replacement for a data exchange
paradigm grounded in robust semantic modeling.



On the following email exchange, I was wondering, if OWL is used for
semantic modeling, are there good ways to accomplish the following:



1.  Generate a wire format schema (for a subset of the model, the subset
they call a "resource"), e.g. XSD



2.  Validate XML instances for conformance to the semantic model.  (Here I'm
reminded of Clark and Parsia's work on their Integrity Constraint
Validator:  http://clarkparsia.com/pellet/icv )



3.  Map an XML instance conformant to an earlier version of the "resource"
to the current version of the "resource" via the OWL semantic model



I think it'd be great to get a semantic web perspective on this fresh look
effort.



Cheers,

Dave







Dave Hau

National Cancer Institute

Tel: 301-443-2545

Dave.Hau@nih.gov







*From:* owner-its@lists.hl7.org [mailto:owner-its@lists.hl7.org] *On Behalf
Of *Lloyd McKenzie
*Sent:* Sunday, August 21, 2011 12:07 PM
*To:* Andrew McIntyre
*Cc:* Grahame Grieve; Eliot Muir; Zel, M van der; HL7-MnM; RIMBAA; HL7 ITS
*Subject:* Re: A Fresh Look Proposal



Hi Andrew,



Tacking stuff on the end simply doesn't work if you're planning to use XML
Schema for validation.  (Putting new stuff in the middle or the beginning
has the same effect - it's an unrecognized element.)  The only alternative
is to say that all changes after "version 1" of the specification will be
done using the extension mechanism.  That will create tremendous analysis
paralysis as we try to get things "right" for that first version, and will
result in increasing clunkiness in future versions.  Furthermore, the
extension mechanism only works for the wire format.  For the RIM-based
description, we still need proper modeling, and that can't work with "stick
it on the end" no matter what.



That said, I'm not advocating for the nightmare we currently have with v3
right now.



I think the problem has three parts - how to manage changes to the wire
format, how to version resource definitions and how to manage changes to the
semantic model.



Wire format:

If we're using schema for validation, we really can't change anything
without breaking validation.  Even making an existing non-repeating element
repeat is going to cause schema validation issues.  That leaves us with two
options (if we discount the previously discussed option of "get it right the
first time and be locked there forever":

1. Don't use schema

- Using Schematron or something else could easily allow validation of the
elements that are present, but ignore all "unexpected" elements

- This would cause significant pain for implementers who like to use schema
to help generate code though



2. Add some sort of a version indicator on new content that allows a
pre-processor to remove all "new" content if processing using an "old"
handler

- Unpleasant in that it involves a pre-processing step and adds extra "bulk"
to the instances, but other than that, quite workable



I think we're going to have to go with option #2.  It's not ideal, but is
still relatively painless for implementers.  The biggest thing is that we
can insist on "no breaking x-path changes".  We don't move stuff between
levels in a resource wire format definition or rename elements in a resource
wire format definition.  In the unlikely event we have to deprecate the
entire resource and create a new version.



Resource versioning:

At some point, HL7 is going to find at least one resource where we blew it
with the original design and the only way to create a coherent wire format
is to break compatibility with the old one.  This will then require
definition of a new resource, with a new name that occupies the same
semantic space as the original.  I.e. We'll end up introducing "overlap".
 Because overlap will happen, we need to figure out how we're going to deal
with it.  I actually think we may want to introduce overlap in some places
from the beginning.  Otherwise we're going to force a wire format on
implementers of simple community EMRs that can handle prescriptions for
fully-encoded chemo-therapy protocols.  (They can ignore some of the data
elements, but they'd still have to support the full complexity of the nested
data structures.)



I don't have a clear answer here, but I think we need to have a serious
discussion about how we'll handle overlap in those cases where it's
necessary, because at some point it'll be necessary.  If we don't figure out
the approach before we start, we can't allow for it in the design.



All that said, I agree with the approach of avoiding overlap as much as
humanly possible.  For that reason, I don't advocate calling the Person
resource "Person_v1" or something that telegraphs we're going to have new
versions of each resource eventually (let alone frequent changes).
 Introduction of a new version of a resource should only be done when the
pain of doing so is outweighed by the pain of trying to fit new content in
an old version, or requiring implementers of the simple to support the
structural complexity of our most complex use-cases.





Semantic model versioning:

This is the space where "getting it right" the first time is the most
challenging.  (I think we've done that with fewer than half of the normative
specifications we've published so far.)  V3 modeling is hard.  The positive
thing about the RFH approach is that very few people need to care.  We could
totally refactor every single resource's RIM-based model (or even remove
them entirely), and the bulk of implementers would go on merrily exchanging
wire syntax instances.  However, that doesn't mean the RIM-based
representations aren't important.  They're the foundation for the meaning of
what's being shared.  And if you want to start sharing at a deeper level
such as RIMBAA-based designs, they're critical.  This is the level where OWL
would come in.  If you have one RIM-based model structure, and then need to
refactor and move to a different RIM-based model structure, you're going to
want to map the semantics between the two structures so that anyone who was
using the old structure can manage instances that come in with the new
structure (or vice versa).  OWL can do that.  And anyone who's got a complex
enough implementation to parse the wire format and trace the elements
through the their underlying RIM semantic model will likely be capable of
managing the OWL mapping component as well.





In short, I think we're in agreement that separation of wire syntax and
semantic model are needed.  That will make model refactoring much easier.
 However we do have to address how we're going to handle wire-side and
resource refactoring too.





Lloyd

--------------------------------------
Lloyd McKenzie

+1-780-993-9501



Note: Unless explicitly stated otherwise, the opinions and positions
expressed in this e-mail do not necessarily reflect those of my clients nor
those of the organizations with whom I hold governance positions.

On Sun, Aug 21, 2011 at 7:53 AM, Andrew McIntyre <
andrew@medical-objects.com.au> wrote:

Hello Lloyd,

While "tacking stuff on the end" in V2 may not at first glance seem like an
elegant solution I wonder if it isn't actually the best solution, and one
that has stood the test of time. The parsing rules in V2 do make version
updates quite robust wrt backward and forward inter-operability.

I am sure it could be done with OWL but I doubt we can switch the world to
using OWL in any reasonable time frame and we probably need a less abstract
representation for commonly used things. In V2 OBX segments, used in a
hierarchy can create an OWL like object-attribute structure for information
that is not modeled by the standard itself.

I do think the wire format and any overlying model should be distinct
entities so that the model can be evolved and the wire format be changed in
a backward compatible way, at least for close versions.

I also think that the concept of templates/archetypes to extend the model
should not invalidate the wire format, but be a metadata layer over the wire
format. This is what we have done in Australia with an ISO 13606 Archetypes
in V2 projects. I think we do need a mechanism for people to develop
templates to describe hierarchical data and encode that in the wire format
in a way that does not invalidate its vanilla semantics (ie non templated V2
semantics) when the template mechanism is unknown or not implemented.

In a way the V2 specification does hit at underlying objects/Interfaces, and
there is a V2 model, but it is not prescriptive and there is no requirement
for systems to use the same internal model as long as they use the bare
bones V2 model in the same way. Obviously this does not always work as well
as we would like, even in V2, but it does work well enough to use it for
quite complex data when there are good implementation guides.

If we could separate the wire format from the clinical models then the 2 can
evolve in their own way. We have done several trial implementations of
Virtual Medical Record Models (vMR) which used V3 datatypes and RIM like
classes and could build those models from V2 messages, or in some cases non
standard Web Services, although for specific clinical classes did use ISO
13606 archetypes to structure the data in V2 messages.

I think the dream of having direct model serializations as messages is
flawed for all the reasons that have made V3 impossible to implement in the
wider world. While the tack it on the end, lots of optionality rationale
might seem clunky, maybe its the best solution to a difficult problem. If we
define tight SOAP web services for everything we will end up with thousands
of slightly different SOAP calls for every minor variation and I am not sure
this is the path to enlightenment either.

I am looking a Grahams proposal now, but I do wonder if the start again from
scratch mentality is not part of the problem. Perhaps that is a lesson to be
learned from the V3 process. Maybe the problem is 2 complex to solve from
scratch and like nature we have to evolve and accept there is lots of junk
DNA, but maintaining a working standard at all times is the only way to
avoid extinction.

I do like the idea of a cohesive model for use in decision support, and
that's what the vMR/GELLO is about, but I doubt there will ever be a one
size fits all model and any model will need to evolve. Disconnecting the
model from the messaging, with all the pain that involves, might create a
layered approach that might allow the HL7 organism to evolve gracefully. I
do think part of the fresh look should be education on what V2 actually
offers, and can offer, and I suspect many people in HL7 have never seriously
looked at it in any depth.

Andrew McIntyre



Saturday, August 20, 2011, 4:37:37 AM, you wrote:

Hi Grahame,

Going to throw some things into the mix from our previous discussions
because I don't see them addressed yet.  (Though I admit I haven't reread
the whole thing, so if you've addressed and I haven't seen, just point me at
the proper location.)

One of the challenges that has bogged down much of the v3 work at the
international level (and which causes a great deal of pain at the
project/implementation level) is the issue of refactoring.  The pain at the
UV level comes from the fact that we have a real/perceived obligation to
meet all known and conceivable use-cases for a particular domain.  For
example, the pharmacy domain model needs to meet the needs of clinics,
hospitals, veterinarians, and chemotherapy protocols and must support the
needs of the U.S., Soviet union and Botswana.  To make matters more
interesting, participation from the USSR and Botswana is a tad light.
 However the fear is that if all of these needs aren't taken into account,
then when someone with those needs shows up at the door, the model will need
to undergo substantive change, and that will break all of the existing
systems.

The result is a great deal of time spent gathering requirements and
refactoring and re-refactoring the model as part of the design process,
together with a tendency to make most, if not all data elements optional at
the UV level.  A corollary is that the UV specs are totally unimplementable
in an interoperable fashion.  The evil of optionality that manifested in v2
that v3 was going to banish turned out to not be an issue of the standard,
but rather of the issues with creating a generic specification that
satisfies global needs and a variety of use-cases.

The problem at the implementer/project level is that when you take the UV
model and tightly constrain it to fit your exact requirements, you discover
6 months down the road that one or more of your constraints was wrong and
you need to loosen it, or you have a new requirement that wasn't thought of,
and this too requires refactoring and often results in wire-level
incompatibilities.

One of the things that needs to be addressed if we're really going to
eliminate one of the major issues with v3 is a way to reduce the fear of
refactoring.  Specifically, it should be possible to totally refactor the
model and have implementations and designs work seemlessly across versions.

I think putting OWL under the covers should allows for this.  If we can
assert equivalencies between data elements in old and new models, or even
just map the wire syntaxes of old versions to new versions of the definition
models, then this issue would be significantly addressed:
- Committees wouldn't have to worry about satisfying absolutely every
use-case to get something useful out because they know they can make changes
later without breaking everything.  (They wouldn't even necessarily have to
meet all the use-cases of the people in the room! :>)
- Realms and other implementers would be able to have an interoperability
path that allowed old wire formats to interoperate with new wireformats
through the aid of appropriate tooling that could leverage the OWL under the
covers.  (I think creating such tooling is *really* important because
version management is a significant issue with v3.  And with XML and
schemas, the whole "ignore everything on the end you don't recognize" from
v2 isn't a terribly reasonable way forward.

I think it's important to figure out exactly how refactoring and version
management will work in this new approach.  The currently proposed approach
of "you can add stuff, but you can't change what's there" only scales so
far.


I think we *will* need to significantly increase the number of Resources
(from 30 odd to a couple of hundred).  V3 supports things like invoices,
clinical study design, outbreak tracking and a whole bunch of other
healthcare-related topics that may not be primary-care centric but are still
healthcare centric.  That doesn't mean all (or even most) systems will need
to deal with them, but the systems that care will definitely need them.  The
good news is that most of these more esoteric areas have responsible
committees that can manage the definition of these resources, and as you
mention, we can leverage the RMIMs and DMIMs we already have in defining
these structures.


The specification talks about robust capturing of requirements and
traceability to them, but gives no insight into how this will occur.  It's
something we've done a lousy job of with v3, but part of the reason for that
is it's not exactly an easy thing to do.  The solution needs to flesh out
exactly how this will happen.


We need a mapping that explains exactly what's changed in the datatypes (and
for stuff that's been removed, how to handle that use-case).

There could still be a challenge around granularity of text.  As I
understand it, you can have a text representation for an attribute, or for
any XML element.  However, what happens if you have a text blob in your
interface that covers 3 of 7 attributes inside a given XML element.  You
can't use the text property of the element, because the text only covers 3
of 7.  You can't use the text property of one of the attributes because it
covers 3 separate attributes.  You could put the same text in each of the 3
attributes, but that's somewhat redundant and is going to result in
rendering issues.  One solution might be to allow the text specified at the
element level to identify which of the attributes the text covers.  A
rendering system could then use that text for those attributes, and then
render the discrete values of the remaining specified attributes.  What this
would mean is that an attribute might be marked as "text" but not have text
content directly if the parent element had a text blob that covered that
attribute.



New (to Grahame) comments:

I didn't see anything in the HTML section or the transaction section on how
collisions are managed for updates.  A simple requirement (possibly
optional) to include the version id of the resource being updated or deleted
should work.

To my knowledge, v3 (and possibly v2) has never supported true "deletes".
 At best, we do an update and change the status to nullified.  Is that the
intention of the "Delete" transaction, or do we really mean a true "Delete"?
 Do we have any use-cases for true deletes?

I wasn't totally clear on the context for uniqueness of ids.  Is it within a
given resource or within a given base URL?  What is the mechanism for
referencing resources from other base URLs?  (We're likely to have networks
of systems that play together.)

Nitpick: I think "id" might better be named "resourceId" to avoid any
possible confusion with "identifier".  I recognize that from a coding
perspective, shorter is better.  However, I think that's outweightd by the
importance of avoiding confusion.

In the resource definitions, you repeated definitions for resources
inherited from parent resources.  E.g. Person.created inherited from
Resource.Base.created.  Why?  That's a lot of extra maintenance and
potential for inconsistency.  It also adds unnecessary volume.

Suggest adding a caveat to the draft that the definitions are placeholders
and will need significant work.  (Many are tautological and none meet the
Vocab WG's guidelines for quality definitions.)

Why is Person.identifier mandatory?

You've copied "an element from Resource.Base.???" to all of the Person
attributes, including those that don't come from Resource.Base.

Obviously the workflow piece and the conformance rules that go along with it
need some fleshing out.  (Looks like this may be as much fun in v4 as it has
been in v3 :>)

The list of identifier types makes me queasy.  It looks like we're
reintroducing the mess that was in v2.  Why?  Trying to maintain an ontology
of identifier types is a lost cause.  There will be a wide range of
granularity requirements and at fine granularity, there will be 10s of
thousands.  The starter list is pretty incoherent.  If you're going to have
types at all, the vocabulary should be constrained to a set of codes based
on the context in which the real-world identifier is present.  If there's no
vocabulary defined for the property in that context, then you can use text
for a label and that's it.

I didn't see anything on conformance around datatypes.  Are we going to have
datatype flavors?  How is conformance stated for datatype properties?

I didn't see templateId or flavorId or any equivalent.  How do instances (or
portions there-of) declare conformance to "additional" constraint
specifications/conformance profiles than the base one for that particular
server?

We need to beef up the RIM mapping portion considerably.  Mapping to a
single RIM class or attribute isn't sufficient.  Most of the time, we're
going to need to map to a full context model that talks about the
classCodes, moodCodes and relationships.  Also, you need to relate
attributes to the context of the RIM location of your parent.

There's no talk about context conduction, which from an implementation
perspective is a good thing.  However, I think it's still needed behind the
scenes.  Presumably this would be covered as part of the RIM semantics
layer?

In terms of the "validate" transaction, we do a pseudo-validate in pharmacy,
but a 200 response isn't sufficient.  We can submit a draft prescription and
say "is this ok?".  The response might be as simple as "yes" (i.e. a 200).
 However, it could also be a "no" or "maybe" with a list of possible
contraindications, dosage issues, allergy alerts and other detected issues.
 How would such a use-case be met in this paradigm?

At the risk of over-complicating things, it might be useful to think about
data properties as being identifying or not to aid in exposing resources in
a de-identified way.  (Not critical, just wanted to plant the seed in your
head about if or how this might be done.)


All questions and comments aside, I definitely in favour of fleshing out
this approach and looking seriously at moving to it.  To that end, I think
we need a few things:
- A list of the open issues that need to be resolved in the new approach.
 (You have "todo"s scattered throughout.  A consolidated list of the "big"
things would be useful.)
- An analysis of how we move from existing v3 to the new approach, both in
terms of leveraging existing artifacts and providing a migration path for
existing solutions as well as what tools, etc. we need.
- A plan for how to engage the broader community for review.  (Should
ideally do this earlier rather than later.)

Thanks to you, Rene and others for all the work you've done.


Lloyd

--------------------------------------
Lloyd McKenzie

+1-780-993-9501



Note: Unless explicitly stated otherwise, the opinions and positions
expressed in this e-mail do not necessarily reflect those of my clients nor
those of the organizations with whom I hold governance positions.


On Fri, Aug 19, 2011 at 9:08 AM, Grahame Grieve <grahame@kestral.com.au

> wrote:


hi All

Responses to comments

#Michael

> 1. I would expect more functional interface to use these resources.

as you noted in later, this is there, but I definitely needed to make
more of it. That's where I ran out of steam

> 2. One of the things that was mentioned (e.g. at the Orlando
> WGM RIMBAA Fresh Look discussion) is that we want to use
> industry standard tooling, right? Are there enough libraries that
> implement REST?

this doesn't need tooling. There's schemas if you want to bind to them

> 2b. A lot of vendors now implement WebServices. I think we should
> go for something vendors already have or will easilly adopt. Is that the
case with REST?

Speaking as a vendor/programmer/writer of an open source web services
toolkit, I prefer REST. Way prefer REST

> Keep up the good work!

ta

#Mark

> I very much like the direction of this discussion towards web services
> and in particular RESTful web services.

yes, though note that REST is a place to start, not a place to finish.

> At MITRE we have been advocating this approach for some time with our
hData initiative.

yes. you'll note my to do: how does this relate to hData, which is a
higher level
specification than the CRUD stuff here.

#Eliot

> Hats off - I think it's an excellent piece of work and definitely a step
in right direction.

thanks.

> I didn't know other people in the HL7 world other than me were talking
about
> (highrise).  Who are they?

not in Hl7. you were one. it came up in some other purely IT places that I
play

>  5) Build it up by hand with a wiki - it is more scalable really since you

wiki's have their problems, though I'm not against them.

> 1) I think it would be better not to use inheritance to define a patient
as
> a sub type of a person.  The trouble with that approach is that people can

On the wire, a patient is not a sub type of person. The relationship
between the two is defined in the definitions.

> A simpler approach is associate additional data with a person if and when
> they become a patient.

in one way, this is exactly what RFH does. On the other hand, it creates a
new identity for the notion of patient (for integrity). We can discuss
whether that's good or bad.

> 2) I'd avoid language that speaks down to 'implementers'.  It's enterprise

really? Because I'm one. down the bottom of your enterprise pole. And
I'm happy to be one of those stinking implementers down in the mud.
I wrote it first for me. But obviously we wouldn't want to cause offense.
I'm sure I haven't caused any of that this week ;-)

> 3) If you want to reach a broader audience, then simplify the language.

argh, and I thought I had. how can we not use the right terms? But I
agree that the introduction is not yet direct enough - and that's after
4 rewrites to try and make it so....

Grahame


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*--
Best regards,
 Andrew
*mailto:andrew@Medical-Objects.com.au<andrew@Medical-Objects.com.au>

*sent from a real computer*





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-- 
Jim McCusker
Programmer Analyst
Krauthammer Lab, Pathology Informatics
Yale School of Medicine
james.mccusker@yale.edu | (203) 785-6330
http://krauthammerlab.med.yale.edu

PhD Student
Tetherless World Constellation
Rensselaer Polytechnic Institute
mccusj@cs.rpi.edu
http://tw.rpi.edu







-- 
Jim McCusker
Programmer Analyst
Krauthammer Lab, Pathology Informatics
Yale School of Medicine
james.mccusker@yale.edu | (203) 785-6330
http://krauthammerlab.med.yale.edu

PhD Student
Tetherless World Constellation
Rensselaer Polytechnic Institute
mccusj@cs.rpi.edu
http://tw.rpi.edu