Re: Genealogical evidence and data model

Dennis Lee Bieber <wlfraed@[EMAIL PROTECTED]
> writes:

> On Fri, 01 Feb 2008 16:24:12 -0500, Haines Brown
> <brownh@[EMAIL PROTECTED]
> declaimed the following in
> soc.genealogy.computing:

>> A "relation****p event" seems to conflate the categories. An "event"
>> (in the sciences, anyway) refers to a change of state. Yet the
>> child-mother relation is the _result_ of a birth event, but in itself
>> does not refer to a change of state. Also, who are the principles in
>> the case of a person's death? To presume that the death was witnessed
>> seems unwarranted.
>>
> 	I'm an old Ultimate Family Tree user, where the data entries
> were called "events", and the parents were roles in the birth event
> (three common roles: child [the person whose birth is recorded in the
> event], father, mother.. Could also add midwives, doctor, etc.)
>
> 	TMG do***entation refers to the data entry as a "tag"... So
> birth is a tag, relation****p is a tag, death is a tag...

Obviously I was confused by TMG's proprietary meanings. Data entry seems
to define a steady state, rather than event in the sense we normally
use the word. The term "role" refers to a functional relation, but for
it to generate an event it must be a causal relation. GEDCOM includes
functional relations, but not event-generating causal relations.

Allow me (who is profoundly ignorant) to speculate. There seems to be
something we might call states (data as it applies to an individual and
also formal relation****ps among individuals as in a family). Such data
can be stored readily in a flat file. On the other hand, there are also
events (in the sense of changes of state), which are the effect of a
causal rather than a formal relation of individuals, which therefore
can't be represented in a flat file. These two contradictory aspects are
interdependent. An event changes the data, while the data constrains
event generation.

If so, then how do we represent this unity of quite different things?
What comes immediately to mind is an object-oriented database. "Objects"
have both a state and a behavior. In terms of a programming language,
the former is called a "field" and the latter a "method". We could
combine an object-oriented language such as Java with a way to store
data, such as XML. 
 
Being embarrassed by this amateur speculation in such august company,
let me instead turn it into a question. There's a lot of discussion of
XML in genealogy, but my impression it is presumed to be a flat file as
a potential substitute for GEDCOM. However, are object-oriented
databases or languages at all used or even discussed in genealogy? 

--
       Haines Brown, KB1GRM