Lecture 3 Modeling.pdf

Alternative Algebraic Model:Generalized Vector Space Model• independence of index terms– k i : a vector associated with the index term k i– the set of vectors {k 1 , k 2 , …, k t } is linearly independent• orthogonal:k i• k j= 0for i≠j• Theorem: If the nonzero vectors k1, k2, ···, kn are orthogonal, thenthey are linearly independent.– The index term vectors are assumed linearly independent but arenot pairwise orthogonal in generalized vector space model– The index term vectors, which are not seen as the basis of thespace, are composed of smaller components derived from theparticular collection.3-66