A couple of recent studies have provided some rich data about the use of IEEE-LOM metadata. Jean Godby analyses the choice of elements in Application Profiles in a recent article, pulling together data from 35 projects. The focus here is on the choices made by designers of Application Profiles, based on the presumed needs of their audiences. Norm Friesen, in his international LOM survey, has looked at the actual use of metadata in five collections. Here the focus is on which elements are actually populated with values by metadata creators.
(Note: check out the discussion of Jean's paper on edtechpost.)