In memoriam: John Riedl

John Riedl, a professor in the University of Minnesota’s Department of Computer Science and Engineering and world-renowned expert in the field of recommender systems, died on July 15, 2013 after a three-year battle with cancer. He was 51.

A faculty member at the University of Minnesota since 1989, Riedl is known worldwide as a pioneer in the field of recommender systems—a field he was instrumental in creating and nurturing. Recommender systems are information filtering systems that seek to predict the “rating” or “preference” that users would give to an item (such as music, books, or movies) or social element (such as people or groups) based on previous choices.

The impact of Riedl's work is extensive, both in industry and among the research community. Software derived from his research is used by tens of thousands of businesses today.

Riedl was one of the leading figures in the broader field of interactive intelligent systems. He was successful in bringing technological advances into practice. He co-founded the company Net Perceptions in 1996 to commercialize his recommender systems research, successfully growing the company to more than 300 employees and becoming a substantial influence in the field. He worked with several industry and non-profit organizations to transfer University research findings into practical advances.

His work is highly recognized by the research community, and honored with awards such as the 2010 ACM Software System Award. Riedl was also elected as fellow of both the ACM and the IEEE, the highest rank in two leading computer science professional societies. His leadership is reflected in the diverse set of scholarly venues he was invited to lead, including serving as founding co-editor-in-chief of the ACM Transactions on Interactive Intelligent Systems and program co-chair of the ACM Intelligent User Interfaces, ACM E-Commerce, and ACM Computer-Supported Cooperative Work conferences, along with the ACM Recommender Systems conference.

Riedl’s papers have been recognized with numerous awards, and his work has been widely covered in the national and global press, including a feature article in The New Yorker, a segment on Nightline, and articles in The New York Times, The Wall Street Journal, InfoWorld, and PC Magazine.

Riedl's contributions did not end with his research—he was an innovative teacher who created and led a practice-focused course where undergraduate students gained experience in designing and building interactive intelligent systems for the Web, releasing them into wide use, and supporting thousands of users. Riedl was also a guide and mentor to those interested in learning to teach or to improve their teaching, and was honored with several awards including: outstanding teacher awards from the Department of Computer Science and Engineering, the George Taylor Award for Exceptional Contributions to Teaching from the College of Science and Engineering, and the University of Minnesota’s McKnight Distinguished Professorship. He modeled concern for students and quality teaching.

Colleagues and students alike could see how he held inviolable his class preparation time and his office hours. He was an often-consulted mentor by junior faculty, and a valuable resource for faculty seeking counsel on any aspect of teaching and managing students. Riedl had a lasting, inspirational effect on so many undergraduates who, years later, comment on the formative and transformative influence he had on them.

Riedl received his bachelor’s degree in mathematics from the University of Notre Dame in 1983. Subsequently, he attended Purdue University and earned a master’s degree in computer sciences in 1985. After receiving a Ph.D. in computer sciences from Purdue University in 1989, Riedl joined the University of Minnesota Department of Computer Science and Engineering as an assistant professor. He was promoted to an associate professor in 1996 and became a full professor in 2004.

Riedl’s influential research and his leadership in the field brought invaluable visibility to the Department of Computer Science and Engineering and the University of Minnesota. Riedl is greatly mourned by his colleagues and students, who extend their sympathy to his many friends in the broader research community.

Riedl is survived by his wife Maureen, his sons Eric and Kevin, and his daughter Karen and her husband Anthony.