Learn the fundamentals of information extraction in this tutorial from BBN Technologies' Ralph Weischedel, presented at the Johns Hopkins University Summer School on Human Language Technology. Explore core concepts, methodologies, and techniques used to automatically extract structured information from unstructured text data. Discover how information extraction systems identify and classify named entities, relationships, and events within natural language documents. Examine real-world applications and challenges in the field, including approaches to handling ambiguity, context, and domain-specific requirements. Gain insights into the theoretical foundations and practical implementations that drive modern information extraction technologies used in natural language processing and computational linguistics research.