Improving Pointwise Mutual Information (PMI) by Incorporating Significant Co-occurrence
Table 3: 5-fold cross validation comparison of rank coefficients for different measures. The number of word-pairs in each dataset is shown against its name. The best performing measures for each dataset are shown in bold.
['[EMPTY]', 'Edinburgh (83,713)', 'Florida (59,852)', 'Kent (14,086)', 'Minnesota (9,649)', 'White- Abrams (652)', 'Goldfarb- Halpern (384)', 'Wordsim (351)', 'Esslli (272)']
From the results we conclude that the concept of significant co-occurrence improves the performance of PMI. The newly designed measures cPMId and cPMIz perform better than both PMI and CSR on all eight datasets. significant co-occurrence is responsible for the PMI performance improvement. The Spearman rank correlation for cPMIz and cPMId are almost identical. cPMId incorporates corpus level significance in a document count based version of PMI but unlike cPMIz, it does not employ the concept of document level significance.