Ryan Tomayko

An interesting thread on the XML deviant mailing list where Elliotte Rusty Harold is pushing an information model where XML data is very loosely defined—as in no schemas—between producers and consumers. This seems to be in line with ideas put forth by Walter Perry over the past eight years suggesting that Standard Data Vocabularies are the wrong way to go and that everyone needs to just put data out there as XML. Tools like XPath and XSLT will allow different parties to interoperate. This results in very little barrier to publishing data with the expense of requiring consumers of that data to implement at least some customized selection or transformation or logic.

I agree with this view and it forms a large part of the foundation of the databank concept. That is, you need to be able to publish data quickly, whether a standard is available or not, and without having to define a formal schema. This is the first stage in the evolution of a data format. There is a high level of incompatibility between vocabularies describing the same thing but people are kicking the tires and they can do it quickly. But at some point this gets out of control and people need to come together and agree on how to provide that information in a common way, bringing the data format to stage 2. However, until you reach some level of usefulness, going down the schemas/standards road is a big waste of time because the requirements are immature and the use cases are weakly defined (all the SOAP stock quote / weather examples for instance).