His research experience lies in the intersection of Databases and the Semantic Web, focusing in data models and query languages, particularly the standards RDF and SPARQL. Currently is interested in Open Data and Social Machines on the Web. He has published extensively in the area, edited three books, and received three best paper awards at Semantic Web Conferences. He received his Ph.D. (1999) in Computer Science from Wesleyan University. He earned a LIcenciatura en Matematicas from Universidad de Chile, and a M.Sc. degree in Mathematical Logic from Universidad Catolica de Chile.