Hi Barry, I just wanted to drop a quick note that I appreciate

your visit and the inspiring debate. It's not like I am ignoring

your criticism. I have a sceprical approach to the feasibility

of your grand vision of the great all-unifying ontology, which is

of the same origin as my scepticism against the need to pound on

the realism point. In the end, whether we might be optimistic or

sceptical about what humankind will be able to know, what matters

is what we do today in the world where theories are still

developing and shifting.

And I agree with many points regarding the quality we should

strive for when building these things such as a Reference Information

Model or ontologies. Although I do not necessarily buy every

specific solution as to how to do things differently. It might

be neither in your or in my personality to focus on agreement

(if imperfect) rather than harp on the disagreement, but let me

just try an honest attempt:

Your top-level ontological categories to distinguish are:

1) continuant vs. occurrant

2) independent vs. dependent

3) universal - particular - individual

I agree with that split, and I want to think the RIM agrees with

it, although it may look otherwise to you.

If you can -- for a moment -- resolve the sticky point about the

Information model vs. model of the "real world", and if you buy

that the RIM is a model of Information about the world, and therefore

if you implicitly prefix every name of a RIM class C with the

phrase "Information about C", then you might appreciate the

following relation:

HL7 RIM Class Barry Smith's Ontological Categories

----------------------- ------------------------------------

Entity continuant, independent

Role continuant, dependent

Participation occurrant, dependent

Act-Information occurrant, independent

ActRelationship occurrant, dependent

You probably know that we are dealing with the dimension of

universal - particular - individual using the Act.moodCode and

the Entity.determinerCode. It may look strange to you, and it

is not perfect, but we have our reasons, and did not regret this

choice. We can discuss that elsewhere.

Just as you are now, so have we been very interested in

laying down a rich set of well defined relationships, and our

large variety of ActRelationship.typeCode, Role.classCode

(i.e., Entity-Relationship) types are a great step forward

in a context where people didn't even think it mattered to

distinguish a "reason" link from a "composition" link. I hope

you appreciate that as a step forward from where we started

in 1999. Now, when you look at those you find many oddballs,

which is what people have thrown into the mix haphazardly

in the hurry of getting things done. So, don't just pick the

first oddball and declare the whole thing for rubbish please.

We have some contributions to make even in your zoology of

part-like relationships (which are rather simple relationships

to define and think about). We distinguish at least:

- part

- content

- ingredient

- member

which are relevant distinctions that our colleagues thought

were too "philosophical" to even bother with. These distinctions

are not even always made in other ontologies, and certainly not

in the year 1999 when we introduced these.

I think we are missing a notion of

- portion

as opposed to part and member. But have not had the ability to

make the case and show the repercussions of adding this relationship.

We also introduced a common way of quantifying all material

relationships, which is very simple and solves a problem which

has been a subject of great confusion in all ontologies where

such quantification is important (notably all drug "terminologies").

All that does not claim that the definitions couldn't be cleaned

up or made more rigorous, but the distinctions we make have merit

and the way we set up the quantification of these roles work for

what we have been trying to do.

We also introduced the distinction between Participation (and their

types) and Roles, and closed the loop between Role and the scoper,

which I think are novel, significant, innovative and true.

That all does not claim that there are not rough edges, even deep

logical problems that we might get into. But to clear those, we

need to go from a *specific* problem analysis to a *specific*

solution that considers the rationale for the things we have, some

of it documented some passed down only in oral tradition and in

tacit assumptions or common hermeneutic frames of reference

(something tells me that you won't appreciate the latter, but

thought it would fit your use of the word "exegesis" this

morning

It was enlightening to see that even you are not exempt from

producing models you do not totally agree with yourself about.

Such as how to model "food fragments in vomitus." We are loaded

with these issues, which are practical compromises to go forward

even though we may not like it all perfectly.

So, I look forward to more of your constructive criticism in the

spirit of making a good thing better, even shedding off the things

that truly are misguided (see, even I can be a realist sometimes .

But they have to be proven to be misguided and a feasible

alternative has to fill the void that the criticism would create.

I'll be glad to put your specific change proposals forward in

the process of HL7, and will obviously strongly support what I

can see as an improvement.

Two more details:

1) you have trouble interpreting what is meant by saying that

an Act is both the "Performance and its Documentation."

As a implicit principle you have to take that the RIM always

models Information-about Act, Entity, etc. And even once we

realize that we do not model "acts" but "information about acts,"

the explicit identification of "Information about Act" and

"Documentation" is still valid, as it speaks to a perpetual

problem that we have in the discussion of how to construct a

good information model about our domain.

The problem is that there are two very oposed views on how to

model healthcare information. There is one group who thinks

healthcare information is a collection of documents

or "reports", and that modeling healthcare information therefore

means to model "reports".

As opposed to this, many people in HL7 know that we model

information about the healthcare services (acts) which may or

may not be found in a report document, but we believe that

this information about Acts needs to be reflected in the model

based on an analysis of what these Acts are (in "reality" if

you will) and independent of how these may be talked about in

conventional text documents. So, we say, we model the "information"

not the "report". This is the dispute that is behind the statement

that an "Act is both the Performance and its Documentation", it

means that we claim that the RIM Acts model information about

healthcare services, and that we see text documents or hierarchical

arrangements of this information to be a matter of "rendering"

this information in documents and folders etc. and we reject to

have document issues creap into the analysis of Acts in the real

world on which we want to base our model of information about

acts. For instance, we believe that a "reason" is a link between

two Act statements, and that it is not appropriate to model

"reason" simply as a "section of a document" or a mere

"record heading".

We are claiming that the information models that people use

to control acts in workflow-automation should be the same as the

model people use to document acts after they are done with the

work, and that should be the same model as people use who

document historical acts that occurred far in the past. So, in

a sense we are trying to be far more "realists" than those people

who think that all we should care is to model "record structures"

about regardless whether these record structures talk about

acts or carrots in vomitus.

Don't know if that helped to reach out.

2) I am puzzled by your issue regarding the symmetry of

the "adjacency" relation.

Clearly on the instance level, adjacency is symmetric, but

why do we have to conclude that adjacency must therefore

be symmetric on the universal level?

It seems to me that the situation can be described in the

following way:

Let R be a relation:

R : (A union B) x (A union B)

which means that

some a in A, b in B satisfies b R a

Why are you surprized that just because the following

axioms are true

forall a in A : a R b => b in B

and

forall b in B : b R a => a in A

which lead you to think that the relation is symmetric,

that it then does not follow that

forall b in B : some a in A : b R a?

Just because

some Cytoplasma is-adjacent-to Nucleus

and Nucleus is-adjacent-to some Cytoplasma

does not mean that

all Cytoplasma is-adjacent-to Nucleus.

This problem is reminescent of what the S-E-P triplets are

addressing. The notion of "Cytoplasma" is a homophone, as it

can mean:

S) cytoplasmatic matter

E) the entirity of the cytoplasma of a cell, or

P) a part or portion of cytoplasma

So, while it may be said that in nucleated cells, the

entirity of cytoplasma is adjacent to the nucleus, it is

certainly not true to say that every portion of cytoplasma

is adjacent to the nucleus, nor does it even make sense

to say that "cytoplasmatic structures" have any adjacency

to anything.

Also, of course there are both nuclei that are not adjacent

to cytoplasma and there are denucleated cells which have

cytoplasma which has no adjacency to a nucleus at all times

(erythrocytes.)

Is this touching your issue at all? I couldn't quite see

how this would be an example for the sort of logical problems

that Rutherford and Goedel went into with the logical

foundation of mathmatics. I actually agree that your project

will have to answer to the problem that not even Rutherford

can solve for Mathematics, but I didn't follow your example

as even getting near the illustration of such a problem?

So, thanks again for your visit, the inspiring discussions,

and sorry for the long email about this large pile of things

that have accumulated.

kind regards,

-Gunther

--

Gunther Schadow, M.D., Ph.D. gschadow@regenstrief.org

Associate Professor Indiana University School of Informatics

Regenstrief Institute, Inc. Indiana University School of Medicine

tel:1(317)630-7960 http://aurora.regenstrief.org