‘Linked’ Data and ‘Open’ Data « Linked Data Horizon Scan
‘Linked’ Data and ‘Open’ Data
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There is some confusion evident in the way that the terms ‘Linked Data,’ ‘Open Data,’ and ‘Linked Open Data’ are used, often almost interchangeably. SWEO’s ‘Linking Open Data’ project did much to exacerbate this trend, as it grew beyond its original scope to embrace data that were not technically ‘Open.’
2For clarity, ‘Linked Data’ should normally be presumed to respect Berners-Lee’s four rules[1]. ‘Open Data’ is harder to pin down with precision, but could usefully be considered to cover data respecting the terms of the Open Knowledge Definition[2]. This definition comprises 11 clauses providing detail around the core premise that ‘open’ data should be freely available online for use and re-use. A number of licenses[3] have been found to be conformant with the Open Knowledge Definition, and should be used where feasible in order to unambiguously assert that data are being made available for re-use.
31Linked Data may be Open, and Open Data may be Linked, but it is equally possible for Linked Data to carry licensing or other restrictions that prevent it being considered Open, or for Open Data to be made available in ways that do not respect all of Berners-Lee’s rules for Linking. In order to avoid confusion, the terms ‘Linked’ and ‘Open’ should be used with care.
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Image by Leigh Dodds
1A recent exercise by Leigh Dodds of Talis partially illustrates the issue[4]. The now-familiar cloud diagram of Linked Data projects is often referred to as the ‘Linked Open Data Cloud’ or ‘Linking Open Data Cloud,’ in deference to the SWEO project from which it evolved. Yet Dodds’ analysis clearly illustrates that the majority of datasets carry no explicit open license. It is also questionable whether the licenses chosen in certain cases are appropriate, given the difficulty of applying Copyright-based licenses such as those from Creative Commons to factual data. The work of groups such as the Open Data Commons[5] is relevant in developing licenses appropriate to the use and reuse of data, and should be evaluated for use within Higher Education.