Instead of comparing microbe and bacterium directly with their PPDB 2.0 score, we look up all of the paraphrases of microbe and all of the paraphrases of bacterium, and compare those two lists.
we form notional word-paraphrase feature vectors v p i and v p j where the features correspond to words with which each is connected in PPDB, and the value of the k th element of v p i equals P P DB 2.0 Score(i, k).