Eliciting Disease Data from Wikipedia Articles
Table 2: Classifier performance determined from 10-fold cross-validation.
['[BOLD] maxNGramLeng', '[BOLD] Precision', '[BOLD] Recall', '[BOLD] F1 score']
(Stanford’s default value is 6). The maxNGramLeng option determines sequence length when training. We were somewhat surprised to discover that larger maxNGramLeng values did not improve the performance of the classifier, indicating that more training data are likely necessary to further improve the classifier. Furthermore, roughly maximal performance is achieved with maxNGramLeng=4; there is no tangible benefit to larger sequences (despite this, we concentrate on the maxNGramLeng=6 case since it is the default). Our 14-article training set achieved precision of 0.812 and recall of 0.710, giving us an F1 score of 0.753 for maxNGramLeng=6.