In order to produce a ranking score, the confidence that the document contains an action-item is: where s is a sentence in document d, π is the classifier's 1/0 prediction,λ is the score the classifier assigns as its confidence that π(s) = 1, and n(d) is the greater of 1 and the number of (unigram) tokens in the document.
when any sentence is predicted positive, the document score is the length normalized sum of the sentence scores above threshold.