1. A non-transitory computer-readable medium comprising instructions for execution by a computer, the instructions implementing steps in a method comprising: storing search results at a server based on a search engine query, wherein said search results comprise a plurality of items; generating at the server a first set of clusters responsive to the search engine query, wherein each of said items is associated with at least one cluster in said first set of clusters; sending the first set of clusters to a terminal configured to display the first set of clusters; receiving at the server user input consisting of an indication to recluster the search results; generating at the server a second set of clusters, wherein said second set of clusters excludes one or more clusters from said first set of clusters, and wherein each of said items is associated with at least one cluster in said second set of clusters; and sending the second set of clusters to the terminal configured to display the second set of clusters, wherein each cluster is defined by a cluster title, and wherein generating at the server a second set of clusters comprises excluding from the second set of clusters one or more cluster titles used in said first set of clusters, excluding the literal phraseology of at least one cluster title in the first set of clusters from the second set of clusters, and excluding a linguistic equivalence class corresponding to at least one cluster title in the first set of clusters from the second set of clusters, and wherein generating the second set of clusters comprises excluding each displayed cluster of the first set of clusters from the second set of clusters.