What leads to interoperability? Lessons learned from Dublin Core and DOI
Interoperability is a desired feature when people access Web content, and there is a long way towards this dream. In general, interoperability on the Web can be abstracted as many users communicating with one another to share information. Two extremes are obvious, (i) achieving a language for all at the cost of minimal information can be exchanged, and (ii) achieving a language for each pair so that such pair can maximally exchange information. These two extremes may converge when the users are homogeneous, i.e. from the same community and hosting similar information.While the simplicity and flexibility of Dublin Core (DC) have attracted many followers, they also lead to limited interoperability among DC applications. The comments in [2] made an interesting analogy: “Dublin Core applications are like snowflakes - no two are exactly the same”. For example, dc:date neither restricts the range of the value (that leaves no place of quality validation) nor offers clear enough semantics of that property (it works more like a legal document that needs lawyers’ interpretation). More researchers [1,3] criticized DC that such limited interoperability may restrict automated metadata processing and thus made DC useless.
Digital Object Identifier (DOI), on the other hand, has fast growing instance data space in the publishing industry. Unlike DC, DOI requires more agreements including (i) more mandatory properties, (ii) more restrictions on the value of properties; and (iii) a federated metadata registration mechanism. These features ensure better structured and interoperable DOI instance data.
From the above study, we may raise the following hypotheses:
1. simplicity and flexibility can lower adoption cost, but they should be carefully enforced to avoid damaging interoperability
2. restrictions (e.g. the range of property value) can ensure data quality and thus promote interoperability
3. making more information interoperated among systems is preferred to making all systems interoperating
4. interoperable metadata should support non-trivial automated data integration, such as and reference resolution.
Further readings
[1] Beall, J. (2004), “Dublin Core: an obituary“, Library HiTech News, Vol.21, No. 8, pp 40-1,
[2] Jill Hurst-Wahl (2007), “Dublin Core?”, (the comment is more interesting than the blog) access on July 15, 2008
[3] Allan Cho (2008), “Dublin Core is Dead, Long Live MODS“, access on July 15, 2008
Li Ding