  Automatic relation extraction (RE) for types of interest is of great
importance for interpreting massive text corpora in an efficient manner.
Traditional RE models have heavily relied on human-annotated corpus for
training, which can be costly in generating labeled data and become obstacles
when dealing with more relation types. Thus, more RE extraction systems have
shifted to be built upon training data automatically acquired by linking to
knowledge bases (distant supervision). However, due to the incompleteness of
knowledge bases and the context-agnostic labeling, the training data collected
via distant supervision (DS) can be very noisy. In recent years, as increasing
attention has been brought to tackling question-answering (QA) tasks, user
feedback or datasets of such tasks become more accessible. In this paper, we
propose a novel framework, ReQuest, to leverage question-answer pairs as an
indirect source of supervision for relation extraction, and study how to use
such supervision to reduce noise induced from DS. Our model jointly embeds
relation mentions, types, QA entity mention pairs and text features in two
low-dimensional spaces (RE and QA), where objects with same relation types or
semantically similar question-answer pairs have similar representations. Shared
features connect these two spaces, carrying clearer semantic knowledge from
both sources. ReQuest, then use these learned embeddings to estimate the types
of test relation mentions. We formulate a global objective function and adopt a
novel margin-based QA loss to reduce noise in DS by exploiting semantic
evidence from the QA dataset. Our experimental results achieve an average of
11% improvement in F1 score on two public RE datasets combined with TREC QA
dataset.
