17. The computer-implemented method of claim 16 , wherein assigning the primary category describing the item of interest from the first search index further comprises identifying a selected number of the first categories based on their relevance values as first category candidates.
17. The computer-implemented method of claim 16 , wherein assigning the primary category describing the item of interest from the first search index further comprises identifying a selected number of the first categories based on their relevance values as first category candidates. 18. The computer-implemented method of claim 17 , wherein assigning the primary category describing the item of interest using the first search index further comprises selecting a deepest common ancestor of the first category candidates as the primary category, wherein the deepest common ancestor comprises the first category candidate that is common to more of the first category candidates than all other first category candidates.