“…As surveyed in (Bonthu et al, 2021), the approaches used to tackle ASAS often fall into two categories. One is based on traditional machine learning techniques such as SVM (Gleize and Grau, 2013;Mohler et al, 2011;Higgins et al, 2014), K-means (Sorour et al, 2015, Linear Regression (Nau et al, 2017;Heilman and Madnani, 2015;Higgins et al, 2014), and Random Forests (Higgins et al, 2014;Ramachandran et al, 2015;Ishioka and Kameda, 2017), all of which heavily rely on the input of manually-crafted features. For example, Sultan et al ( 2016) devised a set of features which were based on a lexical similarity (i.e., similarities between words identified by a paraphrase database (Ganitkevitch et al, 2013)) and monolingual alignment (Sultan et al, 2014), and input the designed features to a ridge regression model to obtain the score of an answer.…”