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Home -> Community -> Usenet -> comp.databases.theory -> Re: The naive test for equality
dawn wrote:
> VC wrote:
>>dawn wrote:
>>>VC wrote:
>>>>...If the modellers chose the
>>>>name/label "source" and did not define what
>>>>entity the name refers to, then the name is just
>>>>meaningless, like say "fshsalkfd". Apparently,
>>>>your hypothetical modellers are not modellers
>>>>but some kind of impostors.
>>>
>>>It is usually much more subtle than that. Everyone agrees that we need
>>>to know whether or not someone is a fullTimeStudent. Ignore the fact
>>>that this would likely be a derived attribute -- it illustrates the
>>>problem. After some sessions with folks from many departments, the
>>>analyst works to get more precision and sits down with someone who
>>>knows all of the tuition rules, along with another person ('cause the
>>>analyst is no rookie) and they nail down this attribute with the
>>>precision of a surgeon.
>>>
>>>The system goes live and the financial aid people are irate! Federal
>>>aid has just been removed from students because they were no longer
>>>flagged as being a fullTimeStudent when by the standards for this
>>>financial aid, they clearly ARE a fullTimeStudent.
>>>
>>>Then you find out that these two departments use the very same term and
>>>might even both have external reasons to use the very same term, and
>>>they use it with just slightly different meanings.
>>
>>Apparently, the analysts made a mistake in assuming that the set of
>>fullTimeStudents is equal to the set of studentsEligibleForFinancialAid.
This assumes perfect and lasting information at modelling time.
> In this case, yes, but it also happens frequently where such a term is
> used the same when the analysis is done, but something changes
> (government regulation or something more subtle) that changes the
> meaning slightly for one group and not another, so that these
> differences creep in.
>
>>I did not claim that one can correctly >>analyze a complex system at one go, >>it's an iterative process of trial end error.
>>Besides, your example is *not* about naming >>issues (as you understand yourself)
>>-- presumably there >>was no ambiguity about the "student" entity .
This is a sub-thread about synonym/homonym problems, but this group does not tend to change the subject line appropriately (I tried a few times, but it did not really work). In the sub-thread your contribution is right on the mark, IMO. Received on Thu Aug 11 2005 - 12:58:07 CDT
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