ZURÜCK

3.4.1.1: Vector Space Model of IR:

Let D={d1,...,dm} be a set of documents and A={A1,...,An} be a set of attributes. A document vector wi=(wi,1,...,wi,n)Rn for a document diD is defined by a set of weights {wi,kR, k=1,...,n} . In the same way a query vector q=(q1,...,qn)Rn is defined for a query.
If further a similarity measure s:Rn×Rn->R is given that assigns a real value to every pair of vectors, the whole system is called a vector space model of IR.

In text retrieval the attributes are in general defined by the occurrence of terms in the text. In this case the weight wi,kR describes the importance of term tkT for the document diD . In the same way the weight qkR describes the importance of term tkT for the query.


ZURÜCK

© 1998 / HTML-Version 17. 11. 1998: R. Ferber