At 23:57 30-10-2000 +1100, Jim Croft wrote, in reply to Bob Morris:

...

The material at http://www.cs.umb.edu/efg/ThieleDraft/thiele_0_3.html illustrates our efforts to draft an XML Schema from Thiele's draft proposal version 0.3 ("TDD0.3") and illustrate its utility with simple applications manipulating a taxonomic treatment.

No-one seems to be commenting on this, at least on the list... is it all too scary? With Halloween just around the corner, do these guys deserve to be tricked or treated?

Well, I certainly hope that responses aren't limited to those of us having mailboxes at pi.csiro.au (that is, Kevin, Jim, and myself).

I applaud the effort Bob Morris and Jun Wan have gone to it constructing this example. They have provided a good demonstration of the power of XML and XSLT to hold information and rapidly render it in a variety of forms. I suspect most of us find that a concrete working example of this sort is a lot easier to evaluate than is a relatively abstract discussion of standards.

This is a great attempt at implementation and surely demonstrates that we are on the right track... doesn't it?

It may well be the right track (depending on the desired destination), but there's still a lot of ground to cover before arriving at the final stop...

One thing that might be helpful would be for this group to come up with a short set of basic design goals that indicate what our objectives really are. My understanding is that the developers of XML itself found such a set of goals to be very useful. Their list of goals was (and still is) to quote from the W3C Recommendation for XML 1.0:

"The design goals for XML are: XML shall be straightforwardly usable over the Internet. XML shall support a wide variety of applications. XML shall be compatible with SGML. It shall be easy to write programs which process XML documents. The number of optional features in XML is to be kept to the absolute minimum, ideally zero. XML documents should be human-legible and reasonably clear. The XML design should be prepared quickly. The design of XML shall be formal and concise. XML documents shall be easy to create. Terseness in XML markup is of minimal importance." Can we develop a similar set of goals and principles (perhaps even using some of the XML principles as a basis)?

One other point - Bob Morris said:

My own view is that there should actually be a single standard representation with a bunch of ways to transform between it and other desired representations. The advantage of this is that you need fewer translators to go between representations A and B if everything has a bidirectional representation with a common one, X. The disadvantage is that you change X at the risk of breaking X<->A, thereby breaking A<->B when neither A nor B changed.

The goal of a single standard representation readily translatable into other representations was, of course, the original goal of DELTA, and its advantages are clear. But perhaps the biggest challenge with any such standard is that it needs to be very comprehensive and flexible - ideally, it should be able to store everything that all of the "subsidiary" formats is capable of representing, and do so in such a way that X<->Y translations are as lossless as possible.

Eric Zurcher CSIRO Livestock Industries Canberra, ACT Australia E-mail: Eric.Zurcher@pi.csiro.au