  During time-critical situations such as natural disasters, rapid
classification of data posted on social networks by affected people is useful
for humanitarian organizations to gain situational awareness and to plan
response efforts. However, the scarcity of labeled data in the early hours of a
crisis hinders machine learning tasks thus delays crisis response. In this
work, we propose to use an inductive semi-supervised technique to utilize
unlabeled data, which is often abundant at the onset of a crisis event, along
with fewer labeled data. Specif- ically, we adopt a graph-based deep learning
framework to learn an inductive semi-supervised model. We use two real-world
crisis datasets from Twitter to evaluate the proposed approach. Our results
show significant improvements using unlabeled data as compared to only using
labeled data.
