{ "id": "1809.05710", "version": "v1", "published": "2018-09-15T12:49:41.000Z", "updated": "2018-09-15T12:49:41.000Z", "title": "Alternate Estimation of a Classifier and the Class-Prior from Positive and Unlabeled Data", "authors": [ "Masahiro Kato", "Liyuan Xu", "Gang Niu", "Masashi Sugiyama" ], "categories": [ "cs.LG", "stat.ML" ], "abstract": "We consider a problem of learning a binary classifier only from positive data and unlabeled data (PU learning) and estimating the class-prior in unlabeled data under the case-control scenario. Most of the recent methods of PU learning require an estimate of the class-prior probability in unlabeled data, and it is estimated in advance with another method. However, such a two-step approach which first estimates the class prior and then trains a classifier may not be the optimal approach since the estimation error of the class-prior is not taken into account when a classifier is trained. In this paper, we propose a novel unified approach to estimating the class-prior and training a classifier alternately. Our proposed method is simple to implement and computationally efficient. Through experiments, we demonstrate the practical usefulness of the proposed method.", "revisions": [ { "version": "v1", "updated": "2018-09-15T12:49:41.000Z" } ], "analyses": { "keywords": [ "unlabeled data", "alternate estimation", "two-step approach", "novel unified approach", "pu learning" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }