For the last 15 years, his primary research interest has been the study of novice programmers. He has published over 100 papers on aspects of computing education. In 2007, he became a fellow of the Australian Learning and Teaching Council, which was one of eight such fellowships awarded that year to Australian academics, across all disciplines. He has been program chair of the International Computing Education Research Workshop, Koli Calling, and the Australasian Computer Education Conference. For seven years, he was a member and three times committee chair of committees that wrote computing exams that were completed by thousands of year 12 high school students in his Australian state of New South Wales. In the last 5 years, he has used neo-Piagetian theory to develop a framework for understanding the intellectual development of novice programmers.