Re: Just one more anecdote

On Tue, 09 Aug 2005 23:32:40 +0200, mAsterdam wrote:

>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.

Hi mAmsterdam,

Yes, it is - combined with a complete set of prescriptions (is that the correct English word?) that will tell you exactly which combinations of values in the extension you'll have to present to the domain expert, and what conclusion to draw from the expert's answer.

It's too bad that Universele Informatiekunde (Nijssen, 1993; published by PNA Publishing BV) was never translated. Despite the many errors it admittedly has, it's still a very good book.

Best, Hugo

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