Some implementations disclosed herein provide techniques and arrangements to train a blocking scheme using both labeled data and unlabeled data. For example, training the blocking scheme may include iteratively: learning a conjunction, identifying first matches in the labeled data and the unlabeled data that are uncovered by the conjunction, and identifying second matches in the labeled data and the unlabeled data that are covered by the conjunction. The conjunction learned in each iteration may be combined using a disjunction. A search engine may use the search engine when searching for records that match an entity.