A novel technique to analyze experiments that have no posttest.

In this work we further evaluate the Bayesian networks method by applying it to real world data from 11 experiment datasets that investigate the effectiveness of various forms of tutorial help in a web based math tutoring system.

Pardos, Z., Dailey, M. & Heffernan, N. (2011). Learning what works in ITS from non-traditional randomized controlled trial data. The International Journal of Artificial Intelligence in Education. 21, 47-63.