Thomas Beale wrote:
> trying hard to understanding this concept...I have a feeling there is
something deep here....
We need to be clear about what can and cannot be done with hierarchical
structures (one to many) and multi-parent structures (many to many).
Hierarchical structures behave in ways that are relatively easy to
understand, but I am not so confident with multi-parent structures. This
applies to any sort of object, whether it be a classification scheme or a
data model. Performing data extraction and analysis using compositional
coding and classification schemes (like SNOMED) is more problematic than
with simple hierarchical schemes (and these have many traps for the unwary).
Is the answer that every multi-parent scheme must be normalised into simple
hierarchies before it can be handled? This is, I think, what is done with
XML fragments and most software programs. Am I missing something obvious to
those with a proper education in information and computer science?
Tim Benson
Abies e-Health
12 St Georges Road, London, NW11 0LR
020 8455 8106; 07768 825 012 (mob); 020 8458 9577 (fax)
[EMAIL PROTECTED]
