Named Entities and Relations

Overview:

Recognizing Named entities and relations among them are essential sub-tasks of natural language understanding and have immediate applications in facilitating access to information. We have developed machine learning and inference techniques for these tasks, focusing on exploiting the inter-dependencies between them as a way to improve performance on each of them.

We have developed a stand-alone, machine learning based, state of the art NE recognition tool, and also studied inference methods that make use of the inter-dependencies between the tasks. Our key approach, which has been developed and studied in the context of several NLP and IE problems is that of Constrained Conditional Models. We found that the use of constraints can significantly improve the performance of both tasks. We also developed this in the context of minimizing the amount of labeled data required for IE extraction tasks, including semi-supervised and active learning protocols.

Relevant Publications: