[sc34wg3] Alignment of N0396 with N0393

Jan Algermissen sc34wg3@isotopicmaps.org
Tue, 29 Apr 2003 22:57:25 +0200

Lars Marius Garshol wrote:
> * Lars Marius Garshol
> |
> | My first question about this document is how it is intended to be
> | used. Is it just a rough draft showing a first attempt at a SAM-RM
> | mapping that is intended to live together with SAM and RM, or is it
> | intended as a replacement for N0396? Clarification on this would be
> | welcome.
> * Jan Algermissen
> |
> | Well, it shows the approach to be taken for expressing the ontological
> | commitments of N0396 in terms of N0393.
> I meant in terms of the ISO process.

I think that this alignment has been requested by the N0396ers, yes?
My intend was clarification and advancement of both 'camps'.

> * Lars Marius Garshol
> |
> | The subtle problem is that the merging rules are wrong. Subject
> | identifiers and source locators share a namespace,
> * Jan Algermissen
> |
> | Oh, what does that mean?
> See section 3.4.5, equality rule, fourth bullet point. I'm also pretty
> sure you don't implement the fifth bullet point there.

Yes, I forgot bullet point 4, but that is just another merging rule to
be added.

The issue with the [reifier] property (point 5) isn't an issue, because
the [reifier] and [reified] properties are obsolete when the SAM is based
on N0393. There is only one surrogate for a single subject anyway.

> * Lars Marius Garshol
> |
> | Further, base names are here merged if they have the same string
> | value,
> * Jan Algermissen
> |
> | They are not. Why do you think so.
> |
> | What do you mean by 'base name'? The name(-string) or the naming
> | characteristic?
> The characteristic.
> Maybe I am wrong here, but if so I really need help on figuring out
> what is going on. Let's say we have a topic with three topic names:
> "Norway" in the scope "English", "Norge" in the scope "Norwegian", and
> "Norway" in the scope "English" (again). Could you walk us through the
> RM representation of this and merging that would happen to it, and show
> how the RM would know what to merge at each step?

This requires a lot of ASCII art and I don;t have the time to do that
now. Will do as soon as I can.

> | Well, it surely can but in our conversation we figured out already
> | that the prose of N0393 is not clear enough for a number of people
> | to understand how.
> The latter part of your sentence is certainly true. Being walked
> through an example might help me understand it, however.
> * Lars Marius Garshol
> |
> | SAM associations are also modelled as RM assertions, despite the fact
> | that these are structured differently,
> * Jan Algermissen
> |
> | Why are N0396 associations structured differently from N0393
> | assertions?
> You know that perfectly well, having just explained the rationale for
> it to Dmitry. See your own posting at <URL:
> http://isotopicmaps.org/pipermail/sc34wg3/2003-April/001767.html >

Well, it is a constraint imposed on assertions, but the structure is
identical besides that.

I did not include the mapping of multiple players of a role to
a single player (that is the set) for purposes of clarity. I expected
you to 'find' this lapsus though ;-)

The solution is in my reply top Dmitry.
> * Lars Marius Garshol
> |
> | Another subtle problem is that a number of things that are handled by
> | the infoset formalism in the SAM is done by prose in the RM,
> * Jan Algermissen
> |
> | Which ones?
> Come on, Jan. Here's one example, from your description of PR_Scope:
>   "Topics that exhibit a value for this property must be surrogates
>    for relationships (that is, they must exhibit a value for the
>    property IS13250::a-sidp)."
> I'm not sure if it does so correctly, but obviously it does try to say
> that scope only applies to topic names, occurrences, and associations.
> (When you add variants it will apply to those as well.) The SAM
> handles this through the formalism, by specifying a property on
> certain item types.

Surely the XML will eventually have to include machine processable
constraints, but, uh, should I have made the effort to develop them
for this illustrative syntax?

Or do you think it cannot be done at all?

> | The prose of N0393 may be unclear, but I don't see how the infoset
> | formalism is more clear that a property based model?
> Compare the documents, then. How hard do you think it is to understand
> N0396, compared to understanding N0393 and N0406?

I am not sure. It took me quite a while to *really* understand N0396,
(what the reasons for certain design choices are, etc.)

Given that there were/are still quite a few wrong/unprecise pieces of
prose in N0396 and noone is asking questions about it, I wonder how many
people did really read and understand it.

In other words: the fact that noone objects to it, doesn't imply it is

> | So do you think that a 15+ pages document is less complicated than a
> | 3 pages XML doocument (that can evetually even be processed by
> | software)?
> Yes. Also, you are not comparing apples and apples here. The 3-page
> thing does not implement all of SAM, nor is it self-contained.


> As for "processed by software" I think you will have to wait a while
> for software that can read a sentence like
>   "Values are equal if the first strings of the pairs are byte
>   identical and the second strings of the pairs are byte identical."

Come on Lars, I certainly don't mean to do NLP here.

> and implement it correctly. The same applies throughout. N0393 and
> N0406 are both very far away from being implementable, and automated
> implementation of N0406 you can forget about so long as it remains in
> anything like its present form.

Yeah sure, use your imagination a bit ;-)

> | The draft alignment contains a suggestion for a slight modification
> | of the model in N0396 in order to reduce the complexity of that
> | model. I'd be curious what you think about this proposed change.
> It has been considered many times by the authors of N0396 over the
> past two years, and we have discussed it on this mailing list several
> times, but we have always decided against it for many different
> reasons. The costs of supporting reification for roles in name and
> occurrence assignments 

Why is that more costly? Doesn't that depend on how the topic map
will be queried?

> and obscuring the conceptual structure of the
> model 

"Obscuring the conceptual structure" ??

What structure? Doesn't N0396 define the struture? How can
the document that defines the structure at the same time obscure it?


I am puzzled.


> were among the chief arguments against it.
> I think you can find more discussion on this in the "occurrence
> variants" thread.
> --
> Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
> GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >
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Jan Algermissen                           http://www.topicmapping.com
Consultant & Programmer	                  http://www.gooseworks.org