1. A non-transitory computer-readable medium embodying a program executable in at least one computing device, wherein the program, when executed, causes the at least one computing device to at least: determine an attribute of an item and a value for the attribute of the item; locate a node in an item taxonomy; determine a rule specified by the node for generating an item family, wherein the rule specifies that the item family comprises at least one item that shares a common value with each item in the item family for each of at least one specified attribute; generate the item family according to the rule; associate the item family with the node; determine that the item family exhibits a predefined taxonomical error condition, wherein the predefined taxonomical error condition comprises at least one of: the item family comprising a single item; the item family comprising zero items; or the item family comprising a number of items exceeding a predefined threshold; and send an electronic message indicating that the item family exhibits the predefined taxonomical error condition.