What is a DOI?
Writing about web page http://dx.doi.org/
Jenny here: even though it looks like Alejandro wrote this, he had used my computer to show me something and was signed in!
Since CrossRef has launched its new tool for parsing simple text references and finding DOIs to match (see previous posting), Alejandro and I were discussing what is a DOI, how this relates to OpenURL, and what has CrossRef got to do with it all?
The DOI is a Digital Object Identifier.
My understanding as a non-techie is that the DOI has emerged over the years as the predominant form of identifier for electronic texts in the academic community. There are other forms, such as the electronic isbn and issn, the URI and the PURL. However, I read about most of these when I first qualified in librarianship way back in 2000, and since then I have come across the DOI and the electronic isbn/issn most often. The electronic isbn/issn is not that useful in linking to the electronic content, not least because it is used to refer to an entire book or journal, whilst the content being at chapter or article level is often the part that people want to link to. When we build OpenURLs for journal articles in the RIU or through Build-a-Link, we actually use the print issn as this is most consistent. The DOI can be used to link directly to the item it is assigned to. (See the linked page that you can use to generate a link if you know the DOI.)
The OpenURL is a way of linking to a journal article using metadata or bibliographic or reference details – whatever you want to call them! It is basically a base string which relates to the provider of the electronic text and then a formatted combination of metadata.
So what does CrossRef have to do with both of these? Well, CrossRef acts as a clearing house for DOIs for scholarly and academic content. You can use CrossRef to find the DOI for an item. The publishers and providers register their content with CrossRef. CrossRef provides a resolver so that the publisher has a base string for an OpenURL. However, not every provider that has DOIs and that is registered with CrossRef also uses the OpenURL resolver facility (eg BioMed Central doesn’t use it but does register its content and DOIs with CrossRef.) Not every item on the CrossRef catalogue appears to have a DOI, and not every item that has a DOI is on CrossRef.
Clear as mud, isn’t it?!