1. A machine-readable storage medium that includes instructions for assembling a sub-pool from a pool of questions, wherein the sub-pool satisfies one or more constraints, in connection with creation of a standardized test comprising the sub-pool of questions, wherein such instructions, when executed by a computer, cause the computer to: A. create a hierarchical representation of the sub-pool, wherein the hierarchical representation comprises a root node and at least one other node, wherein at least one of the other nodes comprises a terminal node, and wherein the root node is associated with one or more root constraints and each of the other nodes are associated with one or more additional constraints; B. form a candidate question set comprising randomly selecting a plurality of questions from the pool; C. test the candidate question set against the additional constraints associated with the terminal node; and D. if the additional constraints are satisfied, test at least the candidate question set against the root constraints.