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Re: The stupidest design I ever saw

From: Neo <neo55592_at_hotmail.com>
Date: 10 Apr 2006 20:05:27 -0700
Message-ID: <1144724726.943338.28130@v46g2000cwv.googlegroups.com>


> > First there is no systematic method that allows one to create the
> > hierarchy (fig 2) on the basis of the table (fig1) (even after ignoring
> > the top most and bottom most nodes which represent Universal and NULL
> > respectively). If you know what that method is, please state it so that
> > anyone can verify it.
>
> 1. Identify all the cylindric sets
> 2. Connect nodes with the partial order relation

I challenge anyone to follow the above steps and create the shown hierarchy from the table, where the names of objects and classes are simply identified by different letters (to prevent a user from introducing knowledge not encoded in the table).

> > Please state THE
> > square/cell to uncheck which unclassifies cartoon as a mammal
> > without also unclassifying Garfield and Snoopy as cartoons?
> >
> > ______ cartoon real dog cat mammal
> > Garfield __X___ ___ ___ _X_ __X____
> > Snoopy __X___ ___ _X__ ___ __X____
>
> This is not big deal.

And yet, your response didn't indicate which cell to uncheck to unclassify cartoon as a mammal as you alluded earlier.

> Any classification system has to obey transitivity rule:
> if class A is a subclass of B and if B is subclass C
> then A has to be a subclass of C.

While classification is transitive in many cases, it is not transitive in all cases. Consider the following class hierarchy:

human

__engineer
____bob
__doctor
____sue

Now a friendly alien from Mars (named bill) arrives on Earth. He is capable of using his tools to dignose health problems and write prescriptions to cure various ailments. This alien is a doctor but he is not a human. To avoid such dilemmas start with a non-hierarcal arrangement of classes as shown below. (It is difficult for you and most other people to realize that there is an indirect, but no direct, relationship between classes human and doctor, which can be derived from the data below).

alien
__bill
human
__bob
__sue
engineer
__bob
doctor
__sue (a human)
__bill (an alien)

> Garfield, which is a cartoon is defined to be a cat. [OK]
> Cat is defined to be a mammal. [This is not encoded in the table]
> Therefore, Garfield is a mammal, even though it is a cartoon. [What?]

I haven't asked if Garfield is a mammal even though it is or isn't a cartoon. The table does not show that cat is a mammal. It only show there are 5 classes listed across the top. It does not show any relationship between the classes. Try replacing the object names and class names with differert letters and you will see you have no basis to make the above statements based on what is in the table. You are introducing your knowledge in deriving relationships among things. Your knowledge is not encoded in the table. Received on Mon Apr 10 2006 - 22:05:27 CDT

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