Information Retrieval

Lecturer: Dr S.H. Teufel (sht25@cl.cam.ac.uk)

No. of lectures: 8

Prerequisite courses: Natural Language Processing, and a basic encounter with Probability is assumed

Aims

The course is aimed to characterise information retrieval in terms of the data, problems and concepts involved. The two main formal retrieval models and evaluation methods are described. The course then covers problems and standard solutions in information extraction, and in question answering.

Lectures

• Information retrieval introduction. Key problems and concepts. Information need. Indexing model. Examples.

• Retrieval models. Vector Space model. Probabilistic model.

• Evaluation methodology. Evaluation and advanced models (relevance feedback, query expansion).

• Search engines and linkage algorithms. PageRank and Kleinberg's Hubs and Authorities.

• Information extraction. Task and evaluation. Lexico-semantic patterns.

• Advanced information extraction methods. Bootstrapping. Learning.

• Question answering. Performance criteria and effectiveness measures, test methodology, established results.

• Outlook and present needs. Relevance of NLP in IR, IE, QA.

Objectives

At the end of this course, students should be able to

• define the tasks of information retrieval, question answering and information extraction and differences between them

• understand the main concepts and strategies used in IR, QA, and IE

• appreciate the challenges in these three areas

• develop strategies suited for specific retrieval, extraction or question situations, and recognize the limits of these strategies

• understand (the reasons for) the evaluation strategies developed for these three areas

Recommended books

Baeza-Yates, R. & Ribiero-Neto, B. (1999). Modern Information Retrieval. Reading, MA: Addison-Wesley and ACM Press.
Spärck Jones, K. & Willett, P. (eds.) (1997). Readings in Information Retrieval. San Francisco: Morgan Kaufmann.
Salton, G. & McGill, M.. (1983). Introduction to Modern Information Retrieval. New York: McGraw Hill.