The SO of a given word is calculated from the strength of its association with a set of positive words, minus the strength of its association with a set of negative words.
the SO of a word, word, is calculated by SO-PMI as follows: where Pwords is a set of 7 positive paradigm words (good, nice, excellent, positive, fortunate, correct, and superior) and Nwords is a set of 7 negative paradigm words (bad, nasty, poor, negative, unfortunate, wrong, and inferior).