@inproceedings{Blackbox, author = {Neil C. C. Brown and Michael K\"{o}lling and Davin McCall and Ian Utting}, title = {Blackbox: a large scale repository of novice programmers' activity}, booktitle = {SIGCSE 2014}, year = {2014}, pages = {223--228}, location = {Atlanta, Georgia, USA}, publisher = {ACM}, address = {New York, NY, USA}, }