I've seen several attempts to define open data and open datasets.
While most of these definitions list several useful and important requirements of often datasets, I do not think they are not yet to be considered authorative. I also think they are rather incomplete.
For open data to be useable, it needs to come with provenance, and it should be accompanied with some sort of policy document that says something regarding its maintenance (or lack thereof) and procedures for resolving disputes and correcting errors. While just dumping the data in the public domain seems to be all some "open data" people want, if you actually care about the data being usable for serious work, having it in the public domain without ownership/accountability/maintainability defined, is probably the last thing you want. You want freedom (to reuse and to share), yes. But you also want transparency regarding who is in charge of the data and who provides QA (even if the answer is "no-one").
The closest thing I've come to addressing these concerns is the ODDC Assessing open data supply report. This is a working document, and it doesn't adress all my concerns, but it is a good start.
However, the ODDC report is a scoreboard, not a definition. And it doesn't address provenance, granularity, the role of providers as interpreters (by means of selection or aggregation), etc. just to name a few of what I regard as omissions.
My question is basically: Does there exist an authoritative definition of an open dataset that takes these type of considerations into account?
If the answer to this is "no", my follow-up question: Does there exist some sort of organization, community or international NGO that attempts to create this type of definition? I.e. something that people such as myself can get involved in to move such an (hopefully to-become authoritative) definition forwards?
(In the world of Free and Open Source Software, there are - for instance the the the Open Source Initiative and the Free Software Foundation, who attempts to supply such an definition for the term "Free and Open Source Software" - or rather "Open Source Software" and "Free Software" - since they can't even agree on what to call it. I hesitate to cite these organizations as examples, because the long going rivalry and partisanship between them is of course not something I would like to see replicated in the open dataset community. But I think their heart and their aspirations are in the right place, while the way they carry out their mission has potential for improvement).