In particular, we calculated the similarity between the two questions using machine translation evaluation metrics, as suggested in (Guzmán et al., 2016).
we used BLEU (Papineni et al., 2002); NIST (Doddington, 2002); TER v0.7.25 (Snover et al., 2006); METEOR v1.4 (Lavie and Denkowski, 2009) with paraphrases; Unigram PRECISION; Unigram RECALL.