Rocchio Relevance Feedback Algorithm

A relevance feedback method in vector‑space retrieval that updates an original query vector by forming a weighted linear combination of the original query and the centroids (average vectors) of judged relevant and nonrelevant documents, typically q' = αq + β(1/|R|)Σv_r − γ(1/|NR|)Σv_nr with tunable weights α, β, γ.