Although MT-Tri is outperforming Self-Adapt in 8 domainpairs, it is noteworthy that MT-Tri is using a larger feature space than that of Self-Adapt.
mT-Tri is using 5000 dimensional tf-idf weighted unigram and bigram vectors for representing reviews, whereas we Self-Adapt uses a 300 dimensional BonG representation computed using pre-trained GloVe vectors.