  We present SwellShark, a framework for building biomedical named entity
recognition (NER) systems quickly and without hand-labeled data. Our approach
views biomedical resources like lexicons as function primitives for
autogenerating weak supervision. We then use a generative model to unify and
denoise this supervision and construct large-scale, probabilistically labeled
datasets for training high-accuracy NER taggers. In three biomedical NER tasks,
SwellShark achieves competitive scores with state-of-the-art supervised
benchmarks using no hand-labeled training data. In a drug name extraction task
using patient medical records, one domain expert using SwellShark achieved
within 5.1% of a crowdsourced annotation approach -- which originally utilized
20 teams over the course of several weeks -- in 24 hours.
