34. A computerized search and presentation system for a set of items, comprising: server coupled to a network; a user terminal coupled to the network; an application running on a computer while stored in the computer's active memory, and stored on the server and the user terminal, wherein the application is configured for: assigning one or more Attributes to each item in the set of items; further assigning to each Attribute, and to no item, a single Kind; creating assignments between Attributes and Kinds, where the assignments assign to each Attribute a single Kind, and to each Kind an arbitrary number of Attributes; assigning to each Kind at least one scheme of transitive implications among the Attributes such that each Kind is associated with several Attributes; determining which Attributes of each Kind are broad Attributes, broad Attributes being Attributes that do not within the set of items imply any other Attribute; presenting to a user a list of Kinds by which the set of items may be grouped; upon accepting the user's selection of one or more Kinds, listing one or more broad Attributes of that Kind; upon accepting the user's selection of one or more of the broad Attributes, presenting information about a subset of items having the selected one or more broad Attributes; wherein Kinds are not assigned to items.
39. The system of claim 34 , wherein assigning an Attribute to an item is tested: by look-up table; during user interaction by testing assignment of an Attribute that implies the Attribute; by a computational procedure that tests the item directly for the Attribute; or any combination thereof.