3. Collecting the metadata

To create a DOI for an instrument, you need to collect all the metadata that describe the instrument and you want to register in the DOI record. Section PIDINST metadata schema in the PIDINST White Paper describes the metadata that you should consider to include.

The Persistent Identification of Instruments WG has developed a PIDINST Metadata Schema. But since you are going to create a DataCite DOI, you will be constrained to use the DataCite Metadata Schema. For that purpose, the PIDINST WG has also provided a Mapping of the PIDINST Schema onto the DataCite Schema

3.1. Mapping of PIDINST metadata onto DataCite

Based on the mapping provided by PIDINST WG, in the following we will discuss how the metadata describing the instrument can be best represented in the DataCite Schema:

The DOI that you are going to create. Add as DataCite property Identifier with identifierType=DOI.
The URL of the landing page that the PID resolves to. The DataCite Schema does not have a property for this, but you’ll register the URL along with the metadata when creating the DOI.
The name by which this instrument is known. Add as DataCite property Title with titleType=Other.
The organization or individual that manages the instrument. Add as DataCite property Contributor with contributorType=HostingInstitution. Consider also to add an identifier for the owner in the nameIdentifier subproperty of Contributor.
The organization or individual that built the instrument. Add as DataCite property Creator. Consider also to add an identifier for the manufacturer in the nameIdentifier subproperty of Creator.
The name of the model or type of the instrument. Unfortunately, as of this writing, the DataCite Schema has no suitable property for that, so you’ll need to leave it out.[1]
A textual description of the device and its capabilities. Add as DataCite property Description with descriptionType=Abstract.
A classification of the type of the instrument. There is no dedicated property for this in the DataCite Schema, but you may add keywords providing such a classification in the property Subject.
The variables or physical properties that the instrument measures or observes. Unfortunately, the DataCite Schema has no suitable property for that, so you’ll need to leave it out.
Relevant events pertaining to this instrument instance. Add as DataCite property Date. Use dateType=Available to indicate the date that the instrument is or was in operation. Use a single date if the instrument is still in operation, to indicate a start date. Use a date interval to indicate a start and an end date, if the instrument has already been decommissioned.
This can be used to establish links to related resources. The DataCite Schema has a property with the same name, having very similar subproperties and semantics as the PIDINST Schema.

To be used if this instrument is also registered elsewhere. Add as DataCite property AlternateIdentifier. Use alternateIdentifierType=SerialNumber for a serial number attributed by the manufacturer. Use alternateIdentifierType=InventoryNumber for an inventory number used by the owner.

Note that as opposed to the PIDINST schema, alternateIdentifierType is free text in the DataCite schema. Thus, when adding an alternate identifier that is not a serial number or an inventory number, you are not forced to use alternateIdentifierType=Other, but may set the appropriate type in alternateIdentifierType right away.

3.2. Additional properties in the DataCite Schema

There are a few more properties in the DataCite Schema that have no counterpart in the PIDINST Schema and that either need to be set because they are mandatory in DataCite or that are worth considering. Of course, any other DataCite property not mentioned here may be considered as well, if it makes sense for a particular use case.

“The name of the entity that holds, archives, publishes, prints, distributes, releases, issues, or produces the resource” (quote from the definition in the DataCite Schema). It’s not quite clear what that would mean in the case of an instrument and it seem to be a little redundant with what would be the Owner in the PIDINST Schema. But it is mandatory in the DataCite Schema, so it needs to be set. We recommend to set it to the entity that created the DOI and is responsible for maintaining the DOI metadata.
Mandatory in the DataCite Schema. We suggest to set it to the year of issuing the DOI.
DataCite DOIs are for many different types of objects, so there is a need to indicate the type. This is mandatory in the DataCite Schema. Obviously, for an instrument DOI there should be an indication that this DOI identifies an instrument instance. In DataCite, ResourceType is free text, but it has a subproperty resourceTypeGeneral having a controlled list of values with defined types of resources. Unfortunately, as of this writing, non of these values would fit for an instrument, so we recommend to set ResourceType to Instrument with resourceTypeGeneral=Other.[2]
This is optional in the DataCite Schema, but it may be useful to acknowledge external funding that supported the purchase or the creation of the instrument.
[1]There is a Proposal to add a Series property to the DataCite Schema that would be suitable to put the instrument model once the proposal is adopted.
[2]There is a Proposal to add Instrument to the controlled list of values for resourceTypeGeneral in the DataCite Schema.