1. Schema level – Efforts are focused on the elements of the schemas, being independent of any applications. The results usually appear as derived element sets or encoded schemas, crosswalks, application profiles, and element registries.
2. Record level – Efforts are intended to integrate the metadata records through the mapping of the elements according to the semantic meanings of these elements. Common results include converted records and new records resulting from combining values of existing records.
3. Repository level – With harvested or integrated records from varying sources, efforts at this level focus on mapping value strings associated with particular elements (e.g., terms associated with subject or format elements). The results enable cross-collection searching.