The following question(s) were asked in the Collection Management Systems Webinar and will be answered here.
Pip Brewer: You indicate that entities should be material or digital. What about concepts? We are focussing here on museum objects and digital surrogates. However, what we are often wanting are individuals/organisms In some collection management systems, these may be represented by multiple records for the same individual (not always related, they may in fact be related only by the first part of the registration number). In fact, the same individual or organism may be represented in collections in multiple organisations/publishers/repositories (e.g., casts, DNA or botanic cuttings shared internationally). For vertebrate skeletons and samples, a single individual could be represented by 50 records. This should be controlled for. So, for “this chipmunk was host of that flea” - the chipmunk could be represented by multiple records - i.e., multiple material and digital entities - should they not be united by a single concept (the individual entity)?
Response:
Yes to almost everything. A dwc:Organism is an Entity for sure. Whether you decide to have it also be a MaterialEntity is a bit philosophical, with data management repercussions.
In the first part of the webinar I said, "We also formally defined the Material- and DigitalEntities as subtypes of Entity, which means that they can have all the defining characteristics and do all of the same things an “entity of interest” can do. This doesn’t mean Entities must be either MaterialEntities or DigitalEntities, it only means that these two types of Entities are important enough to distinguish as subtypes.
Later in the webinar I described the interpretation of the chipmunk as “an Entity, specifically, a specimen of an Organism that was the result of a collecting Event.” If you look into the data for the Entities in the Arctos case study you will find the chipmunk as a MaterialEntity, as follows:
materialEntityID: 21714980
materialEntityType: dwc:Organism
Being modeled as a MaterialEntity, the chipmunk also has a corresponding Entity record:
entityID: 21714980
entityType: Organism
I mapped the data this way because the Organism was collected in its entirety. Having this record of the entire Organism enables exactly what you are talking about in terms of the Organism as the connector to all the associated parts and media. It would work just as well if the Organism was an abstract Entity without instantiation as a MaterialEntity. Philosophically, it would probably be best to distinguish the Organism from the material it consists of and the state it is in at a given time. In this view, an Organism would always be an Entity and not a MaterialEntity, even though it is made up of material throughout its existence. Thinking of the above example this way, there would be an Entity for the Organism, as follows:
entityID: 21714980
entityType: dwc:Organism
with a MaterialEntity for what ended up in a collection looking something like:
materialEntityID: materialEntityID1
materialEntityType: whole organism
And EntityRelationships for these two distinct Entities:
entityRelationshipID: er_id9
subjectEntityID: 21714980
entityRelationshipType: has part
objectEntityID: materialEntityID1
entityRelationshipID: er_id10
subjectEntityID: materialEntityID1
entityRelationshipType: part of
objectEntityID: 21714980