11. A computer-implemented method comprising: selecting, from a search corpus, a set of documents that are relevant to a specified topic; wherein the set of documents includes at least a first document and a second document; for each particular document within at least a subset of the set of documents, extracting one or more lists contained within that particular document and adding the one or more lists into a set of lists; wherein extracting one or more lists includes, extracting a first list from the first document and extracting a second list from the second document; for each particular list in the set of lists, and for each particular item within that particular list, generating an item score for that particular item based at least in part on a number of occurrences of that particular item within other lists in the set of lists; selecting a subset of list items from among all list items in lists in the set of lists based at least in part on the item scores generated for those list items; wherein selecting the subset of list items includes selecting a first subset of items from the first list and selecting a second subset of items from the second list; ranking the selected list items in the subset of list items based at least in part on the item scores generated for the selected list items, thereby generating a ranked master list for the specified topic; and storing the ranked master list in association with the specified topic; wherein the method is performed by one or more computing devices.
11. A computer-implemented method comprising: selecting, from a search corpus, a set of documents that are relevant to a specified topic; wherein the set of documents includes at least a first document and a second document; for each particular document within at least a subset of the set of documents, extracting one or more lists contained within that particular document and adding the one or more lists into a set of lists; wherein extracting one or more lists includes, extracting a first list from the first document and extracting a second list from the second document; for each particular list in the set of lists, and for each particular item within that particular list, generating an item score for that particular item based at least in part on a number of occurrences of that particular item within other lists in the set of lists; selecting a subset of list items from among all list items in lists in the set of lists based at least in part on the item scores generated for those list items; wherein selecting the subset of list items includes selecting a first subset of items from the first list and selecting a second subset of items from the second list; ranking the selected list items in the subset of list items based at least in part on the item scores generated for the selected list items, thereby generating a ranked master list for the specified topic; and storing the ranked master list in association with the specified topic; wherein the method is performed by one or more computing devices. 13. The method of claim 11 , wherein the step of generating the item score for the particular item comprises: adjusting an item score for the particular item based on a rank of an occurrence of that particular item within another list of the set of lists.