TextWiller @ SardiStance, HaSpeede2: Text or Con-text? A Smart Use of Social Network Data in Predicting Polarization

In this contribution we describe the system(i.e. a statistical model) used to participatein Evalita conference 2020, SardiStance(Tasks A and B) and Haspeede2 (TasksA and B). We first developed a classifierby extracting features from the texts andthe social network of users. Then, wefit the data through an extreme gradientboosting, with cross-validation tuning ofthe hyper-parameters. A key factor for agood performance in SardiStance Task Bwas the features extraction by using Mul-tidimensional Scaling of the distance ma-trix (minimum path, undirected graph) ap-plied on each network. The second sys-tem exploits the same features above, butit trains and performs predictions in two-steps.The performances proved to belower than those of the single-step model