10. The system of claim 7 , wherein the user-navigable database directory includes: one or more beginning, intermediate, and terminal nodes, with each intermediate node associated with at least one of the beginning nodes and one or more terminal nodes, and each terminal node associated with a subset of the plurality of databases; and one or more sets of interactive control features, with each set of control features associated with a corresponding one of the intermediate nodes for enabling the user to query a predefined set of databases including databases associated with each terminal node that is associated with the one of the intermediate nodes.
7. An information retrieval system comprising: a plurality of databases; and a server including a memory that contains instructions that are readable by a processor and cause the processor to: receive a restricted natural language search request; receive a current navigation position within a user-navigable database directory; and execute the search request against a metadata-based profile for each of a plurality of databases within the user-navigable database directory contingent on the current navigation position within the user-navigable database directory so as to search a current database associated with the current navigation position and any subdirectory database associated with the current database.