Snow, E. L., Allen, L. K., Jacovina, M. E., Crossley, S. A., Perret, C. A. and McNamara, D. S. (2016) “Keys to Detecting Writing Flexibility Over Time: Entropy and Natural Language Processing”, Journal of Learning Analytics, 2(3), pp. 40-54. doi: 10.18608/jla.2015.23.4.