Standards-based metadata procedures for retrieving data for display or mining utilizing persistent (data-DOI) identifiers

Table 2 A comparison of the essential features of Methods 1–3

	Method 1	Method 2	Method 3
Persistent identifer	handle	DOI (DataCite)	DOI (DataCite)
Resolution mechanism(s)	locatt query or xml-processing via script or content negotiation	Content negotiation	xml-processing via script
Number of HTTP GET requests for file retrieval	2	2^a	3^a
Metadata standards	10320/loc	–	DataCite schema, OAI-ORE, METS

^aFor requests made directly to http://data.datacite.org/. A request via http://doi.org/ requires an additional HTTP request.

ISSN: 1758-2946