An extended analysis of the persistence of persistent identifiers of the scholarly web

Scholarly resources, just like any other resources on the web, are subject to reference rot as they frequently disappear or significantly change over time. Digital Object Identifiers (DOIs) are commonplace to persistently identify scholarly resources and have become the de facto standard for citing them. This paper is an extended version of work previously published in the proceedings of the 2020 International Conference on Theory and Practice of Digital Libraries (TPDL). We investigate the notion of persistence of DOIs by conducting a series of experiments to analyze a DOI’s resolution on the web, with this work presenting a set of novel investigations to expand on our previous work. We derive confidence in the persistence of these identifiers in part from the assumption that dereferencing a DOI will consistently return the same response, regardless of which HTTP request method we use or from which network environment we send the requests. Our experiments show, however, that persistence, according to our interpretation, is not warranted. We find that scholarly content providers respond differently to varying request methods and network environments, change their response to requests against the same DOI, and even return inconsistent results over a period of time. We present the results of our quantitative analysis that is aimed at informing the scholarly communication community about this disconcerting lack of consistency.