Links on the web break all the time. We frequently experience the infamous “404 – Page not found” message, also known as “a broken link” or “link rot.” Sometimes we follow a link and discover that the linked page has significantly changed and its content no longer represents what was originally referenced, a scenario known as “content drift.” Both link rot and content drift are forms of “reference rot”, a significant detriment to our web experience. In the realm of scholarly communication where we increasingly reference web resources such as blog posts, source code, videos, social media posts, datasets, etc. in our manuscripts, we recognize that we are losing our scholarly record to reference rot.
As part of The Andrew W. Mellon Foundation funded Hiberlink project, the Prototyping team of the Los Alamos National Laboratory’s Research Library together with colleagues from Edina and the Language Technology Group of the University of Edinburgh developed the Robust Links concept a few years ago to address the problem. Given the renewed interest in the digital preservation community, we have now collaborated with colleagues from DANS and the Web Science and Digital Libraries Research Group at Old Dominion University on a service that makes creating Robust Links straightforward. To create a Robust Link, we need to:
The first step can be done by submitting a URL to a proactive web archiving service such as the Internet Archive’s “Save Page Now”, Perma.cc, or archive.today. The second step guarantees that the link retains the original URL, the URL of the archived snapshot (memento), and the datetime of linking. We detail this step in the Robust Links specification. With both done, we truly have robust links with multiple fallback options. If the original link on the live web is subject to reference rot, readers can access the memento from the web archive. If the memento itself is unavailable, for example, because the web archive is temporarily out of service, we can use the original URL and the datetime of linking to locate another suitable memento in a different web archive. The Memento protocol and infrastructure provides a federated search that seamlessly enables this sort of lookup.
To make Robust Links more accessible to everyone, we provide a web service to easily create Robust Links. To “robustify” your links, submit the URL of your HTML link to the web form, optionally specify a link text, and click “Robustify”. The Robust Links service creates a memento of the provided URL either with the Internet Archive or with archive.today (the selection is made randomly). To increase robustness, the service utilizes multiple publicly available web archives and we are working to include additional web archives in the future. From the result page after submitting the form, copy the HTML snippet for your robust link (shown as step 1 on the result page) and paste it into your web page. To make robust links actionable in a web browser, you need to include the Robust Links JavaScript and CSS in your page. We make this easy by providing an HTML snippet (step 2 on the result page) that you can copy and paste inside the HEAD section of your page.
During the implementation of this service, we identified two main concerns regarding its sustainability. The first issue is the reliable inclusion of the Robust Links JavaScript and CSS to make Robust Links actionable. Specifically, we were looking for a feasible approach to improve the chances that both files are available in the long term, can continuously be maintained, and their URI persistently resolves to the latest version. Our approach is two-fold:
The other sustainability issue relates to the Memento infrastructure to automatically access mementos across web archives (2nd fallback mentioned above). Here we continue our path in that LANL and ODU, both IIPC member organizations, maintain the Memento infrastructure.
Because of limitations with the WordPress platform, we unfortunately can not demonstrate robust links in this blog post. However, we created a copy with robustified links hosted at https://robustlinks.mementoweb.org/demo/IIPC/robust_links_blog.html. In addition, our Robust Links demo page showcases how robust links are actionable in a browser via the included CSS and JavaScript. We also created an API for machine-access to our Robust Links service.
Lastly, we would like to thank DataCite for granting two DOIs to the IIPC for this effort at no cost. We are also grateful to ODU’s Karen Vaughan for her help minting the DOIs.
For feedback/comments/questions, please do not hesitate and get in touch (martinklein0815[at]gmail.com)!
https://robustlinks.mementoweb.org/
https://robustlinks.mementoweb.org/about/
https://robustlinks.mementoweb.org/spec/
https://robustlinks.mementoweb.org/api-docs/