Tom Perrett wrote:
>
> I thought that XML was a proprietary
> standard (ie Microsoft),
Emphatically not. This is its home: http://www.w3.org/XML/
However, it's not a standard about genealogy or any other subject area.
It's a set of general purpose standards and technologies.
Using these standards and technologies it's possible to specify how data
for some application area be represented. However before specifying
such an application-specific standard one has to work out a data model.
> rather than a proper standard for all such as GEDCOM.
This is the crux of the problem. GEDCOM isn't "a proper standard for
all". It's a file format designed for one particular purpose, the
transfer of material into and out of LDS databases. Its data model is
adequate for that. In fact, it includes a component which exists
specifically to sup****t LDS beliefs. On the other hand it doesn't
provide anything to sup****t situations where one has ambiguities in the
data.
Let me give you an example of what I mean by ambiguities. I would have
no problems in getting GEDCOM to represent my ggg-father and his
descendants. However when I come to his ancestry I have a problem. I
know his father's name, the date of his burial and his age at death. I
know his mother's name, the date of her burial but not her age at death.
I have a copy of the registry record of their marriage. However there
are two individuals of the same name as the father born in the same year
and his age and date of death do not enable me to separate them so
either of these children are candidates. What's more, for one of these
children there were two individuals of the appropriate name and
generation to have been his father. In other words I have three
possible lines to take my ggg-father back two generations. Except I
don't - I have six because there are also two individuals with the same
name as the mother. Admittedly one was somewhat young but not
impossibly so. As far as I'm aware the nearest that GEDCOM could come
to representing this would be as a set of unlinked genealogical
fragments, one starting my gggg-parents marriage and working forwards,
three others representing the alternative lines for my gggg-father and
two representing the alternative lines of my gggg-mother.
In theory this limitation of GEDCOM doesn't prevent someone from writing
a program to represent things in a better way (it might be on my list of
things to do but it never seems to get near the top!). Such a program
would need a data model capable of maintaining alternative links, maybe
attaching a measure of confidence to each. In fact, as I've written in
another post, we don't even need a program to represent this - it can be
done with file cards and paper clips - and nobody has responded to my
challenge to name a package which can emulate this. But if you and I
had such a program and it were confined to GEDCOM as a means of data
interchange it would be quite ***bersome to transfer such data from my
program to yours. My program would have to throw away the information
describing the ambiguities in order to write a GEDCOM. Your program
would then be able to im****t that but we would need to find some other
way of communicating the missing information so that you could enter it
by hand. In practice it seems that the GEDCOM type of model has
influenced genealogical S/W to the extent that there doesn't seem to be
any real advance on it.
--
Ian
Hotmail is for spammers. Real mail address is igoddard
at nildram co uk
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