Ghazarian, Sarik, Ralph Weischedel, Aram Galstyan, and Nanyun Peng. “Predictive Engagement: An Efficient Metric for Automatic Evaluation of Open-Domain Dialogue Systems”. Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 05 (April 3, 2020): 7789-7796. Accessed April 16, 2021. https://ojs.aaai.org/index.php/AAAI/article/view/6283.