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3.4.2: Relation to Boolean Retrieval

Attributes: Ai:D->{0,1}

Ai(d)=1if ti occurs in d0otherwise

Query q=(q1,...,qn)

qi=1if ti occurs in the query0otherwise

If all terms in the query are connected by AND: a document is in the result set, if

Ai(d)=1 i{1,...,n} with qi=1

If all terms are connected by OR: a document is in the result set, if

 i{1,...,n} with qi=Ai(d)=1

This result can be expressed using the inner product of two vectors:

ZUGANG3.4.2.1: Inner Product:

For vectors containing only 0 and 1 the inner product counts the number of positions in which both vectors have a 1.

If all terms in the query are connected by AND: a document is in the result set, if

wi·q=qi

If all terms are connected by OR: a document is in the result set, if

wi·q>=1


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