Ludwig: an online programming tutoring and assessment system. - Steven C. Shaffer (ACM SIGCSE Bull., 2005)

Automated generation and grading of programming assignments (abstract only). - Steven C. Shaffer; Clifford A. Shaffer (SIGCSE, 2013)

Increasing student success by modifying course delivery based on student submission data. - Steven C. Shaffer; Mary Beth Rosson (Inroads, 2013)