CS726 Complete Handouts

Lecture # 2

• Boolean Retrieval Model

ACKNOWLEDGEMENTS

The presentation of this lecture has been taken from the following sources

1. “Introduction to information retrieval” by Prabhakar Raghavan, Christopher D. Manning, and Hinrich Schütze
2. “Managing gigabytes” by Ian H. Witten, Alistair Moffat, Timothy C. Bell
3. “Modern information retrieval” by Baeza-Yates Ricardo,
4. “Web Information Retrieval” by Stefano Ceri, Alessandro Bozzon, Marco Brambilla

Outline

What is Information Retrieval ? ? ?

IR Models The Boolean Model Considerations on the Boolean Model

What is Information Retrieval ? ? ?

Information retrieval (IR) deals with the representation, storage, organization of, and access to information items.

Baeza-Yates, Ribeiro-Nieto, 1999 Information retrieval (IR) is devoted to finding relevant documents, not finding simple match to patterns. Grossman - Frieder, 2004 Information retrieval (IR) is finding material (usually documents) of an

unstructured

nature

(usually text) that satisfy an information need from within large collections (usually stored on computers).

Manning et al., 2007

Information Retrieval

IR Models

Modeling in IR is a complex process aimed at producing a ranking function Ranking function: a function that assigns scores to documents with regard to a given query This process consists of two main tasks: The conception of a logical framework for representing documents and queries The definition of a ranking function that allows quantifying the similarities among documents and queries

IR Models

An IR model is a quadruple [D, Q, F, R(qi, dj)] where

1. D is a set of logical views for the documents in the collection
2. Q is a set of logical views for the user queries
3. F is a framework for modeling documents and queries
4. R(qi, dj) is a ranking function

Retrieval: Ad Hoc x Filtering

Ad Hoc Retrieval: