He was then a postdoctoral fellow, working with Sebastian Thrun and Tom M. Mitchell at Carnegie Mellon University.
He is also the director of the Center for Data Science at UMass, leading a new partnership with the Chan and Zuckerberg Initiative.
[8] In collaboration with John D. Lafferty and Fernando Pereira, McCallum developed conditional random fields, first described in a paper presented at the International Conference on Machine Learning (ICML).
[13] In addition, he was instrumental in publishing the Enron Corpus, a large collection of emails that has been used as a basis for a number of academic studies of social networking and language.
McCallum instigated and directs the nonprofit project OpenReview.net, an online platform that aims to promote openness in scientific communication, particularly the peer review process, by providing a flexible cloud-based web interface and underlying database API.