1. A computer-implemented method: a) initiating formation of a query using controlled vocabulary of ItemSelectors by presenting a plurality of such ItemSelectors to a user for selection on a database interface machine display, each ItemSelector thus presented to the user i) having a Boolean property associated therewith, and ii) having been determined to describe at least one data Item in the database; b) incorporating an ItemSelector selected by the user from among those presented as part of currently selected ItemSelectors; c) changing the ItemSelectors presented to the user as necessary after each user selection such that each ItemSelector presented, when combined according to the corresponding Boolean properties with all other currently selected ItemSelectors, is determined to describe at least one data Item in the database; d) repeating (b) and (c) until a plurality of ItemSelectors are currently selected, including i) at least a first ItemSelector having a first Boolean property associated therewith, and ii) at least a second ItemSelector having a different second Boolean property associated therewith; e) deriving from the selected ItemSelectors a Boolean expression encompassing the first and second ItemSelectors and reflecting the corresponding associated Boolean properties of each ItemSelector; f) associating each of a multiplicity of data Items of a database with a unique corresponding value of a first matrix variable; associating each of a multiplicity of ItemSelectors of the database with a unique corresponding value of a second matrix variable; determining all ItemSelectors associated with each data Item and/or all data Items associated with each ItemSelector; and g) storing the determined associations between ItemSelectors and data Items in an Item-ItemSelector Association array in an electronically readable memory module coupled to the interface machine as a pair of indices of the Item-ItemSelector Association array.
1. A computer-implemented method: a) initiating formation of a query using controlled vocabulary of ItemSelectors by presenting a plurality of such ItemSelectors to a user for selection on a database interface machine display, each ItemSelector thus presented to the user i) having a Boolean property associated therewith, and ii) having been determined to describe at least one data Item in the database; b) incorporating an ItemSelector selected by the user from among those presented as part of currently selected ItemSelectors; c) changing the ItemSelectors presented to the user as necessary after each user selection such that each ItemSelector presented, when combined according to the corresponding Boolean properties with all other currently selected ItemSelectors, is determined to describe at least one data Item in the database; d) repeating (b) and (c) until a plurality of ItemSelectors are currently selected, including i) at least a first ItemSelector having a first Boolean property associated therewith, and ii) at least a second ItemSelector having a different second Boolean property associated therewith; e) deriving from the selected ItemSelectors a Boolean expression encompassing the first and second ItemSelectors and reflecting the corresponding associated Boolean properties of each ItemSelector; f) associating each of a multiplicity of data Items of a database with a unique corresponding value of a first matrix variable; associating each of a multiplicity of ItemSelectors of the database with a unique corresponding value of a second matrix variable; determining all ItemSelectors associated with each data Item and/or all data Items associated with each ItemSelector; and g) storing the determined associations between ItemSelectors and data Items in an Item-ItemSelector Association array in an electronically readable memory module coupled to the interface machine as a pair of indices of the Item-ItemSelector Association array. 14. The method of claim 1 , wherein the ItemSelectors are each of a type selected from a group consisting of words, phrases, position-independent alphanumeric characters, position-dependent alphanumeric characters, numbers of alphanumeric characters in text of a data Item, value ranges, alphabetical ranges, graphical symbols, and pictures.