Improving Pointwise Mutual Information (PMI) by Incorporating Significant Co-occurrence
Table 5: 5-fold cross validation performance of cPMId for various parameter combinations. * indicates a varying parameter.
['Parameters ( [ITALIC] s,  [ITALIC] δ)', 'Edinburgh (83,713)', 'Florida (59,852)', 'Kent (14,086)', 'Minnesota (9,649)', 'White- Abrams (652)', 'Goldfarb- Halpern (384)', 'Wordsim (351)', 'Esslli (272)']
To save space, we show some of the combinations only, though one can see the continuity of performance with gradually changing parameter values. Before comparing cPMId with other measures, we note that while all co-occurrence measures being compared have span threshold s as a parameter, cPMId has an extra tunable parameter δ. While we would like to argue that part of power of cPMId comes from this extra tunable parameter, for an arguably fairer comparison, we would like to fix the δ value and then compare so that all methods have only one tunable parameter s. However most of the conclusions that follow do not change if we were to fix some other δ value, or keep it variable.