I’m constantly encountering confusion about whether something is in the public domain, or whether it’s open access. And it’s no wonder, because the terminology is inherently confusing.

If someone’s heard that material in the public domain is free for the taking, why shouldn’t they think that a blogpost or a tweeted photo — material on domains that are sometimes excruciatingly public — is included in that?

If publishers have heard about how great open access is, why shouldn’t they think that making some content openly accessible on their site is worthy of press releases vaunting how awesome they are?

(That one was a trick question. Publishers shouldn’t think that because it’s their job to be informed about this stuff. When I see a publisher talking about their “open access” site while their footer continues to be blazoned with “all rights reserved”, I don’t assume they just haven’t come across a proper definition before. I assume they’re wilfully taking advantage of the confusing terminology in order to intentionally deceive people while retaining plausible deniability, and they go on my list of Do Not Trust The Evil.)

The opposite of ‘public domain’ isn’t ‘private’; it’s ‘copyrighted’. This means:

• Material created in the 19th century and earlier is mostly in the Public Domain (even if it’s in private ownership) because the copyright has expired.
• Material created recently is generally not in the Public Domain (even if the copyright-holder has made it public by publishing it in a book, a newspaper, a webpage, a social media post, Times Square, and/or laser-writing on the moon) but is rather protected by copyright law. This means the copyright-holder — who is often but not always the author — holds the right to decide what other places the work can or can’t be published in.

The opposite of ‘open access’ isn’t ‘unaccessible’; it’s ‘all rights reserved’.

Something that’s unaccessible can’t be open access; this is true. But being accessible isn’t sufficient. Access has to be guaranteed, either by virtue of the material being in the public domain, or by means of the copyright-holder granting an appropriate license, aka permissions, to users of the material. This allows users to share/take over responsibility for making the material accessible if the copyright-holder can no longer, or no longer wants to, do it themselves.

This is abstract and therefore potentially confusing, so let’s look at a concrete example like Chris Hadfield’s cover of “Space Oddity”. Oh wait — we can’t look at it anymore, because while it was openly accessible for a year, it was never open access. David Bowie’s representatives gave permission for the song to be used for one year, so for one year the video was accessible. But no-one ever gave viewers permission to make and upload their own copies of it to guarantee perpetual access.

(Okay, so users have nevertheless made their own copies and uploaded them all over the place. This is because, firstly, the Internet is forever, and secondly, the video is fantastic. But every single one of these copies is illegal.)

People more familiar with the scholarly publishing landscape may notice I’m almost arguing that green open access and gold open access aren’t actually open access. And you know, I’m okay with saying that an open access article which disappears from the web because the only institutional repository allowed to store it goes down; or an open access journal which suddenly decides to shut all its previously accessible content behind a paywall — that these were never actually open access.

Open access means not just knowing that it’s accessible to everyone now, but knowing that it’s allowed to be accessible to everyone in the future too.