Jerry Mead Simon Gray John Hamer Richard James Juha Sorva Caroline St. Clair Lynda Thomas A cognitive approach to identifying measurable milestones for programming skill acquisition. 182-194 2006 38 SIGCSE Bulletin 4 http://doi.acm.org/10.1145/1189136.1189185 db/journals/sigcse/sigcse38.html#MeadGHJSCT06