A server computing system determines a plurality of statistics for a plurality of test documents, determines a number of false negatives for a corpus of documents based on one or more of the plurality of statistics for the plurality of test documents. The classification of a document of the corpus of documents is a false negative if classification of the document by a classification model is negative and classification of the document by a user is positive. The server computing system calculates an effectiveness of an information retrieval system on a corpus of documents based on the number of false negatives for the corpus of documents.