Relevance feedback:
Given query q, vector d - average vector of the relevant documents, d' - average vector of the irrelevant documents
relevance feedback can be used to create a new query q' for better results.
q = q + d - d'
some variations which can be done
q' = d - d' ( ignore original query q)
q' = αq + (1-α)(d-d')
Kuhu
