Re: Just one more anecdote
Date: Tue, 09 Aug 2005 23:32:40 +0200
Message-ID: <42f920d5$1$11080$e4fe514c_at_news.xs4all.nl>
Hugo Kornelis wrote:
> Kenneth Downs wrote:
> (snip)
>>I've been meaning for some days to look at NIAM, and have not gotten to it. >>It is going to go on the list for this week.
>
> I hope you'll be able to find something. I've never found a good
> description of NIAM on Internet. And the books on NIAM that I know are
> all written in Dutch, and (AFAIK) have not been translated.
>
> Anyway, the symbols used in NIAM and ORM are so much alike that they are
> almost interchangeble. The main difference is in the methods described
> in NIAM to make sure that all relevant questions are asked in an
> interview, that all answers are correct and that therefore the model is
> correct and complete. Unfortunately, that is exactly the part of NIAM
> that I've never seen described anywhere on the 'net...
Maybe a little explanation from an old Nijssen-fan helps here.
The closest thing I read is in english is in Date's
material on external predicates. One could think
of the interviews as investing in getting the
external predicates right, like so:
check example tables against real business data and
busines cases (not unlike UML use cases) with domain experts.
They are called "population diagrams: the table heading (including the predicates) would be called the "intension", the body (including the expansion of the values - by means of the predicate - into the propositions) would be called the "extension". I've used it in practise, some of the systems built on these analyses are still in heavy use.
Well - I'm not going to write the book I'ld like to see here, but this is the core of the NIAM interviews you are referring to as I understood them. Received on Tue Aug 09 2005 - 23:32:40 CEST