Re: domain questionnaire

From: Jan Hidders <hidders_at_REMOVE.THIS.win.tue.nl>
Date: 25 Feb 2001 17:15:46 GMT
Message-ID: <97bek2$sn2$1_at_news.tue.nl>


Vadim Tropashko wrote:

>

> If I'm not certain (is it only me?) about domains in work-of-god
> arena (physics:-), how can I hope to successfully identify domains in
> down-to-earth mess that is created by man?

I bet you are one of those guys that refuses categorically to ask for directions when he is lost. :-) The answer to your question is very simple: you *ask* them. As I said elsewhere, when you are making a data model you are making a model of what the people you are modeling for think that their reality is like. So if they don't know then you cannot model it, by definition. That's why ordinary data modelling is usually simpeler than modelling in the work-of-god arena; it's harder to ask God if your model is right. :-)

> BTW, if you look into archives, you might notice that I was exactly
> at this position a year ago. The fact of not making any progress
> really bothers me.

What is it exactly that you do not understand?

> I fail to understand what the weight domain is, providing that we
> don't know the location of the mass. Shouldnt't an intersection of
> domain with a row give an unambiguous value in a table cell? Or would
> you rather specialize the weight domain as a column "Weight on Earth"
> to achieve this?

The weight is what the user thinks the weight is. If you are saying "yes, but I want to model what 'weight' really is" then you are missing the point.

Kind regards,

-- 
  Jan Hidders
Received on Sun Feb 25 2001 - 18:15:46 CET

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