ASC 1993 ERD
Below is an entity-relationship diagram (ERD) showing the main concepts of an information model for biological collections. This view of basic collections data was validated by experts from virtually every biological discipline in natural history collections, including botany, entomology, invertebrate zoology, ichthyology, mammalogy, and paleontology. Equivalent concepts exist among the organizational "classes" of the Darwin Core and other standards.
This diagram is relevant to our task of elaborating kinds of material samples because it shows that subtyping (subclassing) as a modeling methodology has been used in biodiversity informatics for almost 30 years. The purpose of this model was to begin the design of multi-disciplinary collection management systems (CMS). The benefit of subtyping in that context was to recognize the common and distinct attributes of different kinds of collection objects, and to accommodate the sorting and tracking of objects as they are analyzed and documented.
Although observation data was out of scope in that workshop, it was recognized that this model would work well for presence-only observation data used to document species distributions. The same concepts hold for simple field occurrence observations.
This model did NOT deal explicitly with repeated sampling of the same organism. There was no explicit concept of the organism because in (most) systematics collections most specimens are removed from nature only once, so specimen = organism. It was suggested that cases of an organism being sampled repeatedly in the field (e.g., repeated blood draws in the recapture of a banded [ringed] bird, or repeated cuttings from one tree to document phenology) could be handled by recording an organism identifier (e.g., band code) in the collection-object record.
