Draft Spec mark 2

[Eric Zurcher]

At 08:13 2/09/2000 +1000, Kevin Thiele wrote:
>These are four (very early) examples, not four models. My intention is to
>develop a
>specification that can allow data represented with varying levels of
>complexity, from very simple statements to fully worked up integral data
>files such as Lucid and DELTA use. I'm not sure why, but I like the idea
>that the most basic document would simply say "Eric Zurcher has two feet".
>Perhaps current programs wouldn't be able to make much use of such a
>document, but maybe in the future we may have a way of collecting and
>organising clouds of such basic scraps (atoms) of description into something
>quite powerful.

Well, perhaps. But I think that our successors will appreciate it if we
apply a bit of rigour and take care to describe our data with as much
clarity and lack of ambiguity as possible. I don't think they'd find the
statement "Eric Zurcher has two feet" to be particularly interesting or
even unambiguous. Is "two feet" an anatomical statement, or a measurement
(e.g., has two feet of figurative rope, by which he can easily hang himself
in a forum such as this), or both <G>?

>....

>| I might also note that I strongly question the way the above is organized.
>| I think a rearrangement better expressing the relationships (but still not
>| really addressing the problem of a lack of meaningful validation) would be
>| more along the lines of:
>|
>|         <ITEM>
>|            <ITEM_NAME> Gouania exilis </ITEM NAME>
>|            <ELEMENT>
>|               <ELEMENT_NAME> Flower colour </ELEMENT_NAME>
>|               <VALUE> green
>|                 <QUALIFIER> rarely </QUALIFIER>
>|               </VALUE>
>|            </ELEMENT>
>|         </ITEM>
>
>This is perhaps a subtle point, perhaps a trivial one, and I'm glad you
>raised it. Why is this better that the above? What exactly is the advantage?
>I know yours is more DELTA-like and I agree it seems more intuitively
>correct, but is there more to your strong belief than that? In truth, I
>played with different ways of structuring unitary statements and presented
>the one I did to draw comment rather than just follow down the path of what
>we do already.

I think there is a real difference in terms of a reduction in ambiguity. We
should generally make an effort to clearly associate modifiers with the
object that they are intended to modify. Suppose we have something like the
following:

<ELEMENT>
  <ELEMENT_NAME> leaf </ELEMENT_NAME>
  <VALUE>
     lobed margins
  </VALUE>
  <VALUE>
     with spines
  </VALUE>
  <QUALIFIER>
    rarely
  </QUALIFER>
</ELEMENT>

How should such a construct be interpretted? Do spines cover the leaf as a
whole, or are they confined to the lobed margins? Is it the spines which
are rarely present, or the lobed margins?


Eric Zurcher
CSIRO Division of Entomology
Canberra, Australia
E-mail: ericz at ento.csiro.au