Utilizing pseudo-relevance feedback in fusion-based retrieval

An exemplary method includes: determining a pool of documents, wherein each document is within at least one of a plurality of lists, each of the lists results from executing a query on a corpus, and the corpus comprises at least the pool of documents; determining a first ranking of documents within the pool of documents based at least in part on first scores computed for respective documents within the pool; estimating relevance to the specified query at least of respective documents within the first ranking, wherein the relevance is estimated without user feedback regarding the relevance; and determining a second ranking of documents within the pool based at least in part on second scores computed at least for respective documents within the first ranking, wherein the second score for a given document is computed based at least in part on the estimated relevance of at least the given document.