Well, it's not an article, and I'm guessing that much of it is aimed at a slightly more technical audience than you might have in mind, but in 2002 I gave a DevCon talk, the slides for which Sam Ruby has kindly posted on his Intertwingly blog at [1].  At least one of the slides nets out my views on that, though at a pretty high level.  In case it's of help, the contents of the pertinent slide (#9) are:

What are schemas for? * Contracts:  agreeing on formats * Tool building: know what the data will be before the first instance shows up     * Database integration     * User interface tools     * Programming language bindings * Validation:  make sure we got what we expected

Noah

[1] http://intertwingly.net/slides/2002/devcon/SchemaSecrets.ppt

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Noah Mendelsohn
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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