Mark is a research scientist and assistant research professor of Computer Science at Johns Hopkins University. He works in the Human Language Technology Center of Excellence (COE) and with the Center for Speech and Language Processing (CLSP). Over the years he has worked at a variety of industrial research labs, including Google, IBM and Microsoft. His research focuses on applications of statistical machine learning (artificial intelligence) to natural language processing and medical informatics. His published research with student Michael Paul includes, "You Are What You Tweet: Analyzing Twitter for Public Health" and "A Model for Mining Public Health Topics from Twitter".