Snow, Erica Linn, Laura K Allen, Matthew E Jacovina, Scott A Crossley, Cecile A Perret, and Danielle S McNamara. 2016. “Keys to Detecting Writing Flexibility Over Time: Entropy and Natural Language Processing”. Journal of Learning Analytics 2 (3):40-54. https://doi.org/10.18608/jla.2015.23.4.