Because researchers need to know about retracted papers
RetractoBot automatically emails authors, when papers they have cited are retracted. It is a research project and service from the Evidence-Based Medicine DataLab at the University of Oxford.
Papers are retracted as a result of error or fraud, but retracted papers sometimes continue to be cited as if the research was still valid. Currently researchers who have cited a paper that was later retracted have no way of learning about the retraction, unless they happen to see the retraction notice. This project aims to improve the visibility of retraction notices.
There are tools to help authors spot retracted papers in their citations at the point of submission, but research suggests that plenty of retracted papers are still cited as if they are valid (e.g. Pfeifer and Snodgrass 1990, Korpela 2010, Neale, Dailey, and Abrams 2010). As far as we know, there are no other services alerting authors to retractions of papers they've previously cited.
There is no freely and openly accessible database of all citations. Elsevier have kindly given us access to their citations database. The RetractoBot currently knows about more than 4,000 retracted papers; and over 130,000 papers that cite those retracted papers.
RetractionWatch has written an article about that.
We'll be publishing it with our paper on the project. If you're interested in how we built the service, our code is available.
We welcome all feedback and questions. Get in touch: [email protected].