Data and Non-text Information Types
DDE groups its collections and individual datasets into eight data/non-text information types. When looking at a collection or dataset, it's normally obvious that the main content of the collection or the dataset is one of these "types." That doesn't mean there won't be some overlap, ambiguity, or combinations, but the primary content type can be categorized as one of the eight below.
If there are two data/non-text types with nearly equal representation in a collection, both types will be listed in that collection's citation. If you are browsing or searching for a specific data type, you will retrieve all records indexed as that type, plus all "combination" citations that include your specific type as part, but not all of the content. So, for example, if you browse or search for records that have been identified with the Numeric Data "type," you'll get back all of those plus any records that may have been identified as Numeric Data and Figures/Plots.