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Re: [ontolog-forum] Topic maps and the "wheel" of "logical semantics": w

To: Pat Hayes <phayes@xxxxxxx>
Cc: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Patrick Durusau <patrick@xxxxxxxxxxx>
Date: Mon, 30 Apr 2007 13:09:30 -0400
Message-id: <463622CA.9070805@xxxxxxxxxxx>
Pat,    (01)

Pat Hayes wrote:    (02)

>> Pat,
>> No, not much point in continuing this thread. But I did want to point 
>> out one statement that is simply wrong and misleading:
>>> By the way, the literature of 'Topic Maps' seems to include a kind 
>>> of vague groping towards a semantic theory, but it has not yet 
>>> reached the level of technical sophistication that logical semantics 
>>> reached in the mid-1960s. Sometimes it is a very good idea to not 
>>> try to re-invent the wheel, particularly if you don't know any 
>>> wheelwrights.
>> If that is your impression of topic maps then you are seriously 
>> mis-informed.
>> Topic maps can be boiled down to two assumptions:
>> 1. People identify the same subjects differently.
>> 2. It is possible to disclose a mapping between different 
>> identifications of a subject
> The very idea that there is a subject that can be identified in 
> various ways is what I meant by my (rather impolite, sorry) term 
> 'vague groping'. I have read, or tried to read, quite  a lot of the 
> Topic Map literature, and it seems clear that Topic Maps are just very 
> elementary logic, done in a very peculiar notation and terminology. No 
> doubt you will diagnose me as suffering from logic-fixation, a disease 
> which causes one to see logic even where it is not intended. I will 
> however observe that topic maps have been actively promoted as an 
> alternative to RDF, etc., for SWeb use. (Which indeed was the only 
> reason I came to study them.) So some of their supporters seem to 
> think they have semantic weight.
As I noted below, yes, topic maps can be constructed by those who view 
them as having "semantic weight." (Actually I said they could be 
constructed according to some semantic theory to be precise.)    (03)

>> such that all the information about that subject can be collocated to 
>> a single location.
> Aside from the above, this seems confused. In general, it is not 
> possible to collocate *all* the information about anything in one 
> location. Even encyclopedia articles are not *all* the information 
> about a thing. All the written biographies of Charles Darwin, say, are 
> not *all* the information about him. And even if this were possible, 
> why would one want to do this? What engineering or pragmatic  purpose 
> would it serve? Pointers were invented so that one need not do this.
Well, I don't know if it is your "logic-fixation" or simply bad prose on 
my part but the "all" in that statement referred to all the information 
on a subject in a topic map. I wasn't claiming and I don't really think 
you thought I was, that a topic map contains *ALL* the information known 
about a subject. Not real sure how one would make a judgment of that 
sort anyway.    (04)

As far as the pragmatic purpose, consider the following example. I 
recently did a paper under contract that compared topic maps and record 
linkage, a technique that arose in vital records in the late 1950's. In 
doing that research, I discovered that the same technique has been 
studied under the following names:    (05)

merge/purge, de-duplication, hardening of soft databases, reference 
matching, object identification, identity uncertainty, entity 
heterogeneity, entity identification, object isomerism, instance 
identification, entity reconciliation, list washing, data cleaning, 
deduplication and co-reference resolution    (06)

I should note that more than one mathematical model has been developed 
for the technique, apparently due to failure to discover that the work 
had already been done under another name.    (07)

Gee, you pose a tough question. Why would I possibly want to have 
information about that particular technique gathered together, without 
regard to the means used to identify it? Hmmm, well, perhaps so that I 
would not duplicate research done under another name for the same 
subject? So that I would not have to duplicate the matching that had 
been done by someone else between one or more of these terms? (Noting 
that I don't guarantee that a search on any of these terms will *always* 
return information that is about the same subject as the term "record 
linkage." Not only do people use different terms but sometimes a single 
term is used differently by different people.)    (08)

If that sounds too "academic," imagine you are in a hospital emergency 
room and your physician misses critical information that would have been 
beneficial but was missed because they did not use the terminology 
necessary to find it.    (09)

>> That's it. No attempt to specify a semantic theory or reasoning, etc.
> But that *is* the beginnings of a semantic theory. The first stage of 
> any semantics is the mapping between referring expressions and their 
> denotations, and the most basic semantic relationship is that of 
> identity. Peirce built his whole logic around identity mappings. 
> Really, Topic Maps are not anything fundamentally new; they are a very 
> old idea wrapped up in a new notation and terminology.
Actually topic maps or at least the behavior that topic maps represent, 
the mapping of different identifications of the same subject, is far 
older than Peirce. How do you think people do translations?    (010)

> Logic does not *require* reasoning; but in any case, deriving the 
> conclusion that <this>=<that> is a very simple kind of reasoning.
Oh, part of your logic-fixation again. Yes, you can characterize a 
mapping of <this>=<that> as simple logic if that makes you feel any better.    (011)

>> Anyone can use any basis for identifying a subject and any basis they 
>> like for saying that two or more identifications do indeed represent 
>> the same subject.
> Just as they can in a first-order logical semantic framework.
Oh, you mean like Peirce did in identifying a thief and the porter who 
stole his watch as the same person?    (012)

But more to the point and what seems to be completely ignored in this 
discussion, is that most people don't use first-order semantic 
frameworks to make those mappings.    (013)

Agreed, such mappings can be made in your first-order semantic 
framework. So what? Given the limited number of people who use them, how 
successful are they going to be in generating the number of mappings 
required?    (014)

>> That is not to deny that *particular* topic maps may be constructed 
>> using particular ontologies or semantic theories. XTM topic maps, for 
>> instance, use sets of URIs for subject identification. But that is 
>> *a* choice and does not limit (according to the standards as 
>> currently written) another topic map from making other choices.
>> You can record "logical" properties for subjects if you want to 
>> "reason" about them or any other properties that you find useful.
> There is no such thing as a non-logical property.
Yes, in a very narrow sense. I should have said properties from a 
defined ontology.    (015)

>> Put a bit more expansively, topic maps are an attempt to enable 
>> people who are unaware of the many flavors of ontologies, logic in 
>> any form, etc., to get about the business of identifying their 
>> subjects as well as recognizing and mapping to other identifications 
>> of the same subjects.
> That is a laudable goal, indeed. URNs were created with the same goal.
>> You are free, of course, to use ontologies or logic for such 
>> identifications or mappings, but such tools are not required.
>> Judging from the current state of finding information on any given 
>> subject on the WWW, the wheel of "logical semantics" has been 
>> ignored, is broken or has other concerns.
> It has other concerns. Semantics isn't concerned with finding 
> information in a network. But I don't seem to find Topic maps of any 
> use in this task either. The way to find information is to use a very 
> large hash table, such as Google.
Just because you are not concerned with a problem, such as finding 
information (whether networked or not, topic maps are not limited to 
networked information), doesn't mean that it isn't real or doesn't merit 
a solution.    (016)

That you would suggest very large hash tables shows you haven't devoted 
much thought to the problem. Hash tables, large or otherwise, are not in 
and of themselves an answer to the problem of different identifications 
for the same subject or the same identiification being used by different 
people for different subjects.    (017)

Moreover, with a topic map I can record my mapping between different 
identifications for the same subject, which would be a benefit to the 
next person who searches for that subject under any of its identifications.    (018)

Topic maps are in use by diverse such organizations such as the 
Norwegian Post Office, the IRS, the Office of Naval Intelligence and the 
Y-12 Complex at Oak Ridge, as well as the Danish Royal Library. To name 
only a few.    (019)

Google isn't a solution. It is a symptom of the problem faced by anyone 
who wants to find information about a subject however it is identitified.*    (020)

*(The SW proposal that every subject have a single unique identifier has 
been tried before. Esperanto is the one that comes to mind. I guess that 
is why we are using Esperanto in our exchange isn't it?)    (021)

Hope you are having a great day!    (022)

Patrick    (023)

>> Hope you are at the start of a great week!
> Ditto.
> Pat
>> Patrick
>> -- 
>> Patrick Durusau
>> Patrick@xxxxxxxxxxx
>> Chair, V1 - Text Processing: Office and Publishing Systems Interface
>> Co-Editor, ISO 13250, Topic Maps -- Reference Model
>> Member, Text Encoding Initiative Board of Directors, 2003-2005
>> Topic Maps: Human, not artificial, intelligence at work!
>    (024)

Patrick Durusau
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model
Member, Text Encoding Initiative Board of Directors, 2003-2005    (025)

Topic Maps: Human, not artificial, intelligence at work!     (026)

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