CrossRef Text and Data Mining

Editor's Notes

• #2: Questions at end. Talk a little bit about what CrossRef is then move on to talk about our text and data mining service.
• #3: First just a few words about CrossRef for anyone who isn’t a member or might not be familiar with us as an organisation. CrossRef is a not-for-profit membership organisation of international scholarly publishers. We have 4000 member publishers, representing all disciplines - not just STM, and comprising commercial publishers, academic societies, open access publishers, university presses. We also have 83 affiliate members and 2000 library affiliates - these libraries and other organisations make use of the CrossRef database to look up DOIs and metadata. We are the largest DOI registration agency and have assigned nearly 63 million DOIs to date.
• #4: CrossRef was founded 14 years ago to solve the problem of broken links. The web is all about links, but links break. This is annoying if you’re browsing the web and want to follow an interesting link, but in the context of scholarly publishing it becomes more than annoying - if you can’t follow a citation from one paper to another you’re being hampered in your research. CItation linking is one of the greatest benefits of online publishing, but it really does need to be reliable
• #5: and publishers were finding that web sites changed, content moved, and links that they had put into their articles stopped working. So they started a multi-publisher initiative to solve this problem of broken links. This is done using the DOI - the Digital Object Identifier, which I’m sure many of you are familiar with. A CrossRef DOI is simply a unique identifier for a piece of content. Once assigned, it doesn’t change. It is to all intents and purposes a meaningless number, but it allows that piece of content to be located on the web.
• #6: And it works like this: publishers use CrossRef DOIs to link to content, usually from the references at the end of articles. Users click on those DOI-based links and are referred via the CrossRef database to the cited article at it’s correct location on the web. If content moves the publisher only has to update the CrossRef database once, and all of the publishers that are linking to their content using CrossRef DOIs will be redirected to the content in its new location.
• #7: Every month there are around 90 million clicks on CrossRef DOI links, so 90 million citations resolved to content.
• #9: The issue of Text and Data Mining has become very important and we feel that CrossRef is in a unique position to expand its current infrastructure (a registry of unique identifiers and metadata for scholarly content and thousands of members) to make TDM easier for researchers and their institutions and publishers. Technical solution - we aren’t addressing the issue of licencing.
• #11: Looking at positives. Finding treatments to diseases that may not have been found before.
• #12: But urge caution – Google Flu!
• #13: Why did CrossRef develop this service? Applies to OA content too. Let’s just illustrate these issues.
• #14: Researcher to illustrate that plus some of the publishers we represent. TDM is about scale.
• #15: Bilateral agreements aspect - In the past, researchers who wish to text and data mine published literature have no common or simple way of accessing the full text for the content they wish to mine. This is true both of subscription-based content as well as of open access content. Consequently, TDM users access the content in one or two ways: Negotiating with publishers to have the content delivered to them, either via physical media or bulk data transfer (e.g. FTP) “Screen-scraping” the publisher’s website. The first option doesn’t scale well across multiple Publishers and Researchers. It also presents synchronisation problems if the researchers want an ongoing feed of refreshed content. The issue with the second option is that “screen scraping” is an inefficient, fragile and error prone mechanism for identifying and downloading full text. Screen scrapers put a large performance burden on web sites and, at the same time, any slight changes to the web site can break the tool that is doing the screen scraping. CrossRef Text and Data Mining provides a common solution which works across Open Access and subscription-based publishers and is free for anyone to use.
• #16: Processing the same document on multiple sites could easily skew text and data mining results and traditional techniques for eliminating duplicates (e.g. hashes, etc.) will not work reliably if the document in question exists in several representations (e.g. PDF, HTML, ePub ) and/or versions (e.g. accepted manuscript, version of record) Using the DOI as a key will allow researchers to retrieve and verify the provenance of the items in the TDM corpus, many years into the future when traditional HTTP URLs will have already broken
• #18: The CrossRef Common API is the main aspect of this service and is designed to allow researchers to easily harvest full text documents from all participating publishers regardless of their business model (e.g. open access, subscription). It makes use of CrossRef DOI content negotiation to provide researchers with links to the full text of content located on the publisher’s site. The publisher remains responsible for actually delivering the full text of the content requested. Thus, open access publishers can simply deliver the requested content while subscription based publishers continue to support subscriptions using their existing access control systems.
• #19: API works with content negotiation – what is content negotiation
• #20: Content negotiation allows a user to request a particular representation of a web resource. DOI resolvers use content negotation to provide different representations of metadata associated with DOIs.A content negotiated request to a DOI resolver is much like a standard HTTP request, except server-driven negotiation will take place based on the list of acceptable content types a client provides. Here, they’re asking for text
• #21: Here they’re asking for XML – and can also request PDF too as we know a lot of publishers may only have back content in PDF and that’s fine.
• #23: Set of standard HTTP headers that can be used by servers to convey rate-limiting information to automated TDM tools. Well-behaved TDM tools can simply look for these headers when they query publisher sites in order to understand how best to adjust their behaviour so as not to effect the performance of the site. The headers allow a publisher to define a “rate limit window”- which is basically a time span (e.g. a minute, and hour, a day).
• #25: In order for researchers to use the CrossRef API, Publishers need to add new metadata to their CrossRef DOI deposits.
• #27: One or more URIs pointing at licenses that govern how the full text content can be used.
• #28: This needs to be added to the publisher XML – license information at the article-level. Examples on our support site.
• #30: Publishers who require researchers to agree to a specific set of Terms and Conditions (T&Cs) before they are allowed to text and data mine content that they otherwise have access to (e.g. through an existing subscription) will need to make use of the click-through service.
• #34: So to put it all together…
• #37: If you are an open access publisher or if your existing subscription licenses already allow TDM of subscribed full text, then the registration of the above metadata deposit is the ONLY thing you need to do in order to enable TDM of your content via the CrossRef Metadata API. Rate limiting.
• #38: Rate limiting too
• #39: Support site with info. Info on rate limiting on there too.
• #40: LAUNCH later this month. More deposits from OA publishers at the moment as it’s easier as their licenses already allow text and data mining. Piloted last year and got approval from the board to move it into Production in November which we’ve done to prepare for launch in March.
• #41: Working group which will migrate to a full CrossRef Committee when the service is officially launched seen over 100,000 deposits of full text links and license information, mainly from Hindawi but some from AIP and IEEE as well.
• #42: Eric Lease Morgan
• #43: Publishers and researchers in pilot. Launch in May