Metadata is data about data. The concept of a hierarchical decomposition of data items in successively more restricted data elements is intruiging. It allows to quickly pick an choose data element relevant to a defined task at-hand, and a great deal of flexibility as to the delimitation of individual data fields is maintained, because higher hierarchical levels may effectively represent concatenations of atomic data items. It can cover the needs of large-scale databases as well as the needs of small scale databases or datasets set up by individuals. It is the latter category where most of the original data are stored, their incorporation into large scale databases is often made difficult by inprecise structural defintions.
Data dictionary A fixed list of fields and their description.
It definitly has the advantage to appear quite readable to any biologist and it could still play a role as a simple exchange format. However, in its basic form it does not support structure at all, and we would fail to mirror the consensus reached about at least some of the structural elements present in collection data. Some terms are used in this document which have to be defined in advance. All information related to units which have been incorporated into a collection or a system of observations such as those used in floristic mapping projects. An artificial assemblage of units.