Patterns, correlates, and reduction of  homework copying
David J. Palazzo, Young-Jin Lee, Rasil Warnakulasooriya and David E. Pritchard,
(Phys. Rev. ST Phys. Educ. Res, vol. 6, (2010), p. 010104)

Measuring student learning with item response theory  PDF
Young-Jin Lee, David J. Palazzo, Rasil Warnakulasooriya and David E. Pritchard.
(Phys. Rev. ST Phys. Educ. Res, 4, 010102 (2008))

Mathematical Learning Models that Depend on Prior Knowledge and Instructional Strategies PDF
David E. Pritchard, Young-Jin Lee & Lei Bao
(Phys. Rev. ST Phys. Educ. Res, 4 (1), 010109 (2008))

Time to completion of web-based physics problems with tutoring PDF
Rasil Warnakulasooriya, David J. Palazzo & David E. Pritchard
(Journal of the Experimental Analysis of Behavor, 2007, 88, pp.103-113)

What course elements correlate with improvement on tests in introductory Newtonian mechanics? PDF
Elsa-Sofia Morote and David E. Pritchard
(Submitted to Am. J. Phys. )