An end-to-end data curation system and the various methods used in linking, matching, and cleaning large-scale data sources. The goal of this system is to provide scalable and efficient record deduplication. The system uses a crowd of experts to train the system. The system operator can optionally provide a set of hints to reduce the number of questions sent to the experts. The system solves the problem of schema mapping and record deduplication in a holistic way by unifying these problems into a unified linkage problem.