Why should data be released under the CC0 waiver...

...Instead of a different Creative Commons license, such as CC-BY? Or just with normal copyright restrictions?

(You can get an explanation of CC0 here: it implies relinquishing all rights and essentially means releasing something into the public domain.)

A good question, one that I attempted to answer as part of my Exploring Open Science session at Brock University several weeks back. While I was talking about the importance of Open Data within the Open Science movement, one of the audience members very properly pressed the point of why it's important for data to be open.

I think I gave a pretty good answer but probably not perfect. Of course, I meant to research it a bit more when I got back but never did.

Yesterday Heather Piwowar asked a question on Friendfeed:

Where do you point to for explanation of why data is most appropriately released under CC0 instead of CC-BY?

Aha! I seek to be enlightened and answers appear to be forthcoming.

Two online resources were suggested, both excellent:

CC0 use for data

CC0 is particularly relevant to data. Databases may contain facts that, in and of themselves, are not protected by copyright law. The copyright laws of some jurisdictions cover database design and structure, however, and some jurisdictions like the European Union have enacted special laws to protect databases when they are not protected under applicable copyright law. CC0 is intended to cover all copyright and database laws, so that however database rights are protected (under copyright or otherwise), those rights are all waived. An opinion piece in Nature on "Post-publication sharing of data and tools" explicitly recommends open sharing and the use of CC0 to put data in the public domain:

"Although it is usual practice for major public databases to make data freely available to access and use, any restrictions on use should be strongly resisted and we endorse explicit encouragement of open sharing, for example under the newly available CC0 public domain waiver of Creative Commons."

Remembering Babel: Open Data Sharing & Integration

...Even a simple requirement like attribution, when aggregated over thousands or millions of data elements, can become a very serious burden. Scientists should provide attribution (and citation) for valid scientific reasons, and no legal requirement may be flexible enough to replace common sense or professional judgment, an important ingredient in deciding what to attribute and how. In addition, license incompatibility problems, which are especially relevant with share-alike licenses, can prevent databases or data sources from being combined or integrated or data from being reused. All of this can have a negative impact on the usability of scientific data.

And I would also suggest looking at the Panton Principles for Open Data in Science, which is what I based my answer on during my Brock presentation.

3. The use of licenses which limit commercial re-use or limit the production of derivative works by excluding use for particular purposes or by specific persons or organizations is STRONGLY discouraged. These licenses make it impossible to effectively integrate and re-purpose datasets and prevent commercial activities that could be used to support data preservation.

   If you want your data to be effectively used and added to by others it should be open as defined by the Open Knowledge/Data Definition - in particular non-commercial and other restrictive clauses should not be used.

4. Furthermore, in science it is STRONGLY recommended that data, especially where publicly funded, be explicitly placed in the public domain via the use of the Public Domain Dedication and Licence or Creative Commons Zero Waiver. This is in keeping with the public funding of much scientific research and the general ethos of sharing and re-use within the scientific community.

   Explicit dedication of data underlying published science into the public domain via PDDL or CCZero is strongly recommended and ensures compliance with both the Science Commons Protocol for Implementing Open Access Data and the Open Knowledge/Data Definition.