22. A computer-readable medium having instructions stored thereon, wherein the instructions, when executed by a computing apparatus, cause the computing apparatus to: receive item information for an item of interest, the item information comprising one or more item attributes and corresponding item attribute values for the item of interest; assign a first category for the item of interest from hierarchically organized first categories stored by a data store; identify a category attribute of the assigned first category; obtain one or more hierarchically organized second categories that comprise the identified category attribute and a corresponding category attribute value; determine one or more second category candidates based at least in part upon an assessment of the relevance of the item information with each of the second categories; and assign one of the second category candidates a second category for the item of interest based at least in part upon the hierarchical positions of the second category candidates with respect to one another such that at least one of the remaining second category candidates is a sub-category of the second category.
22. A computer-readable medium having instructions stored thereon, wherein the instructions, when executed by a computing apparatus, cause the computing apparatus to: receive item information for an item of interest, the item information comprising one or more item attributes and corresponding item attribute values for the item of interest; assign a first category for the item of interest from hierarchically organized first categories stored by a data store; identify a category attribute of the assigned first category; obtain one or more hierarchically organized second categories that comprise the identified category attribute and a corresponding category attribute value; determine one or more second category candidates based at least in part upon an assessment of the relevance of the item information with each of the second categories; and assign one of the second category candidates a second category for the item of interest based at least in part upon the hierarchical positions of the second category candidates with respect to one another such that at least one of the remaining second category candidates is a sub-category of the second category. 23. The computer-readable medium of claim 22 , wherein assigning the first category for the item of interest from the first categories comprises assessing the relevance of at least one of the category attributes and category attribute values of respective first categories to the received item attributes and item attribute values.