I was wondering if there were differences between "open data" and "public data"? In this SE group, the two terms seem to be used interchangeably, but I feel that they are not interchangeable.

This excellent page gives a very good definition of open data.

I would contend that public data set, are data in the public domain, but restricted by the data owner's usage and distribution choices, which may bear no resemblance to the . So one set of public data may have a very different usage licensing or distribution restrictions.

Do others have a view on this?

If they are deemed to be different, does Open Data SE also include Public Data?

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    Can you provide a definition of public data? – Patrick Hoefler Feb 22 '16 at 22:02
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    Questions about the scope of the site should probably be asked separately on the Meta site : meta.opendata.stackexchange.com – Joe Feb 23 '16 at 18:41
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    Yes, I'm really struggling to find a definition that I havn't just made up ... happy to make one up, but that's not really appropriate for SE. – Marcus D Feb 23 '16 at 19:18
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    @Joe. This is not a question on the scope of Open Data SE, but rather, if you read a large number of articles, the terms public data and open data are used as the same thing within this site. They are very definitely not, IMO, but I would like others to input on this. I think its a very basic question that most people confuse the two types of data. Just because a set of data is in the public domain, it doesn't mean it can be used in whatever way an individual wants to. – Marcus D Feb 23 '16 at 19:56
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    I know that SE hates 'poll' questions, but you could always ask something like 'when you hear the term 'public data', what do you think it means?' and then post various possible definitions ... but it'd probably be better to do it on meta, so the folks who insist on closing all of the interesting questions leave it alone. – Joe Feb 23 '16 at 20:06

The difference between Public Data and Open Data is in its release:

Open Data is data that is released with expressed re-use ability baked in. The data is released in an open data format, by an (ideally) authoritative source with a license attached that allows for re-use/remix of the data by anyone, without restrictions.
Public data is data that is released to the public that has some form of restriction(s) placed on it. These restrictions typically come from proprietary sources: data released in proprietary data formats, time sensitive releases, licensing from proprietary means used in creation, accessing, and re-using/re-mixing the data, etc.

PDFs are the textbook example of what is Public Data: data that has been released to the public, but includes barriers to access, editing, and re-use/re-mix. Even though PDF has been released by Adobe, its still tied to a contentious release that includes some technologies that are still owned and not shared by Adobe. While it is possible to create machine-readable PDFs, not to mention PDFs with attachments and accessible PDFs, I have yet to see two of these in the wild, and neither have you. The one that I have seen, was for a presentation by Adobe, and has since yet to be replicated, at least at a basic level of consumption whereas it would be noticeable.

The reluctance of Openness communities to define and own these terms makes them much more explosive the longer they are allowed to fester alongside each other. Without definition, there is no structure.

  • This seems more like a personal opinion than an accepted definition. PDF is a pretty horrendous format, true, but its abuse doesn't preclude it being used to publish open data. Tools such as Tabula and Poppler allow you to extract text from some PDFs. – scruss Mar 2 '16 at 17:41
  • its not open if you have to take steps to extract it. its not reusable/remixable out of the box. which is what i said. and what you are saying in your answer – albert Mar 2 '16 at 17:51
  • I think the PDF example is not data related, that is a proprietary presentation format. – Marcus D Mar 2 '16 at 19:29
  • not according to adobe – albert Mar 2 '16 at 23:34
  • so zipped csv isn't open, as you have to take steps to extract it? – scruss Mar 3 '16 at 0:19
  1. Open Data meet the Open Definition.
  2. Public Data are viewable by all, but don't meet the remixability or format standards of Open Data. Examples of public data would be current stock prices or news stories; you can get them if you pay for them, but you can only use them according to the owner's limitations.

These definitions would also depend on whether you're in a country that has database/collection rights or not.

Purely as my opinion, public data discussion does not belong on OpenData SE.

  • its not public if you have to pay for it. thats private. – albert Mar 2 '16 at 17:51
  • "you can get them if you pay for them" ... I disagree, you can get them, because they are in the public domain ... they cost nothing to "get", but ... to use, they must be used within the conditions of that particular data provision. That may include payment, but may not. – Marcus D Mar 2 '16 at 20:16

Well, let me state what is common between them and then the difference. In both the case, the common thing is that it is publicly available for access. Every website has some public data which is open for access. So that data is publicly available and therefore is similar to open data in terms of access.

However, the moment you talk about using the data that is publicly available on a website, the difference should become clear. Public data is publicly available for access on websites but cannot be re-used or redistributed. It would lead to a score of violations of copyright and what not.

However, in the case of open data, that is not the case. It cannot just be accessed but also re-used and redistributed without any restrictions. In this way, both can be accessed but both cannot be re-used and redistributed. You can click here to read more about it.

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