Human users want to search, browse, retrieve, ingest, process. Computers require prescribed vocabularies, formats, and protocols. There should be two or more to allow the market to influence future evolution to accommodate new technology, new methods. The use of object methods with inheritance, persistence, etc will help. Metadata is a conceptually deep problem that will never be solved completely.
Data modeling is an essential part of the solution.
Progress will come as many motivated groups tackle the identification and organization of metadata appropriate to their domains of interest. The project team is charged with creating a system capable of 1GB throughput, pedabytes of capacity, 1B files, and 1500 simultaneous users. They need to implement a metadata system that will enable automatic navigation and access in the system, with appropriate security, location transparency, and resistance to failure. There may be terabytes of metadata. Their technology solution is DCE and the Encina TP Monitor.