“…Several researchers extracted single set feature groups such as N-grams (Wongkoblap et al, 2017), Bag-of-Words (Benton et al, 2017;Nadeem, 2016), LIWC (Paul et al, 2018) or LDA (Coppersmith et al, 2015;Maupomé et al, 2018) for diagnosing depression in user postings. Other studies (Resnik et al, 2015;Preoţiuc-Pietro et al, 2015;Nguyen et al, 2014;Schwartz et al, 2014;Tsugawa et al, 2015) compared the effectiveness of each of these distinct characteristics using different machine learning techniques.…”