From Paraphrase Database to Compositional Paraphrase Model and Back
Table 8: Illustrative phrase pairs from Annotated-PPDB with gold similarity >4. The last three columns show the gold similarity score, the similarity score of the RNN model, and the similarity score of vector addition. We note that addition performs better when the pairs have high length ratio (rows 1–2) or overlap ratio (rows 3–4) while the RNN does better when those values are low (rows 5–6 and 7–8 respectively). Boldface indicates smaller error compared to gold scores.
['Index', 'Phrase 1', 'Phrase 2', 'Length Ratio', 'Overlap Ratio', 'Gold', 'RNN', '+']
A few trends emerge from this table. One is that as the length ratio increases (i.e., the phrase pairs are closer in length), addition surpasses the RNN for positive examples. For negative examples, the trend is reversed. The same trend appears for overlap ratio.