25. The method of claim 23 , further comprising: assigning a relevance score to the search result documents, where the formulating the search query refinement suggestion further includes: ranking the clusters based on the relevance score and a number of search documents in the clusters.
25. The method of claim 23 , further comprising: assigning a relevance score to the search result documents, where the formulating the search query refinement suggestion further includes: ranking the clusters based on the relevance score and a number of search documents in the clusters. 26. The method of claim 25 , where the formulating the search query refinement suggestion further comprises: selecting ones of the clusters based on the ranking.