<div>The more I dig into OAI-PMH the more I get the impression having found an initial solution for this so called 'Catalogue Service Protocol' (or whatever it's better name should be...). I wonder why OAI is not more well known given the fact that GOS 2 papers mention it, but I have not found any detailed information. Did anybody do similar investigations?
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<div>What bothers me in search of such a protocol is, that I am not sure whether we have common basic assuptions about the goal of the protocol. CSW 2 does not explain much of these but I suspect that there could be some discrepancies, especially regarding discovery and binding. By harvesting OAI-PMH - and me too - means that (meta) data is queried before hand by a service provider. This does'nt exclude on-the-fly query (basic assumption in CSW?) but it is the preferred mode, because metadata volumes are low and it scales.
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<div>Binding is done using this 'protocol information' I mentioned before - and a subsequent self describing request command - which is probably the only additional DCMI element besides coverage (= bbox) to be specified in the specialized Dublin Core metadata information model. Additional information about service types and or file formats relies on the protocol indicated by the 'protocol information'.
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<div>Jo was enthusiastic to implement something immediately. So why no go with OAI-PMH? We have even the choice of some (almost) ready implementations if you look at <a href="http://www.openarchives.org/tools/tools.html">
http://www.openarchives.org/tools/tools.html</a> as well as <a href="http://sf.net">http://sf.net</a> where a search for OAI gives 27 results.</div>
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<div>-- Stefan</div>