Persistent Identifiers are globally unique numeric and/or character strings that reference a digital object. Persistent identifiers can be actionable in that they enable a user to access the digital resource via a persistent link. They are intended to function for the long term. While there are several standard persistent identifier systems, the most relevant to USGS are Digital Object Identifiers (DOI).
What are DOIs and how are they useful?
A Digital Object Identifier (DOI) is one type of unique, persistent identifier that is permanently assigned to a specific electronic resource. It is sometimes likened to a Social Security Number (SSN) for a person. Just as a person may be assigned a unique number that identifies him or her to various parties – employers, creditors, the Internal Revenue Service – and remains the same no matter where he or she moves, so an electronic object receives a unique sequence of alphanumeric characters that remain tied to that object, no matter how many times the object moves to different servers or property rights owners. A DOI can link an end user to the unique digital object. A DOI supports scientific integrity in that it provides access to the data, workflow, or software version used in a research project from which results can be reproduced.
A DOI is permanently attached to a digital object, and is managed apart from the object's physical location. The DOI itself doesn't change. This provides enormous advantage, because a properly managed DOI will always point to the current online location of that object, and can therefore be used reliably in all references and citations. The reliability of DOIs provides a strong advantage over a cited URL, which does little good for end users if the desired object is no longer available from that electronic location.
A DOI identifies a specific online resource, such as the final version of a dataset or publication that was approved for release, a dataset that was improved and annotated to meet a requirement, or the version of a numerical model that was used in a scientific publication.
USGS Use of DOIs
Two official DOI registration organizations used by the USGS and sanctioned by the Digital Object Identifier Consortium are CrossRef and DataCite.
A DOI name takes the form of a character string divided into two parts, a prefix and a suffix, separated by a slash. The Crossref.org prefix for USGS scholarly series publications is 10.3133. The DataCite.org prefix for USGS data is 10.5066. When a DOI begins with 10.3133, it references a USGS scholarly series publication, and when it begins with 10.5066, it references a USGS dataset or other data product.
Here's what a DOI looks like:
Here's how it becomes an actionable link:
For USGS Publications
Digital Object Identifiers for USGS series publications will be obtained for you when they are released through the USGS publication process specified in the Fundamental Science Practices. These Digital Object Identifiers will originate from the CrossRef system. This DOI assignment is part of the standard USGS publications process.
Example USGS Publication (DOI automatically obtained through CrossRef):
Engott, J.A., Johnson, A.G., Bassiouni, Maoya, and Izuka, S.K., 2015, Spatially distributed groundwater recharge for 2010 land cover estimated using a water-budget model for the Island of O`ahu, Hawai`i: U.S. Geological Survey Scientific Investigations Report 2015–5010, 49 p., https://doi.org/10.3133/sir20155010.
Diffendorfer, J.E., Compton, Roger, Kramer, Louisa, Ancona, Zach, and Norton, Donna, 2014, Onshore industrial wind turbine locations for the United States through July 2013: U.S. Geological Survey Data Series 817, https://doi.org/10.3133/ds817.
For USGS Datasets
All data released through USGS on servers owned by, or managed under contract to, the Bureau must be assigned a DOI generated by the USGS Digital Object Identifier (DOI) Creation Tool; DOIs created using this tool are registered to DataCite.org.
USGS data that are published on Federal servers managed by other agencies may be assigned a DOI managed by the hosting agency, if required as a condition for publishing the data; otherwise, a USGS DOI should be assigned to these data using the USGS DOI Creation Tool. The Data Management Plan should specify where the final data will be published; if another Federal agency will publish the USGS data, the Plan should also stipulate which agency will assign and manage the DOI during the anticipated lifecycle of the data. USGS scientists are encouraged to consult their Bureau Approving Official for questions or further guidance.
Regardless of the assigning agency, the DOI for the data must be referenced in the final metadata record as the link to the data.
Data associated with the scholarly publication (DOI obtained by data owner through DataCite):
Moschetti, M.P., 2017, Database of earthquake ground motions from 3-D simulations on the Salt Lake City of the Wasatch fault zone, Utah: U.S. Geological Survey data release, https://doi.org/10.5066/F7V98691.
McLeod, J.M., Jelks, Howard, Pursifull, Sandra, and Johnson, N.A., 2016, Characterizing the early life history of an imperiled freshwater mussel (Ptychobranchus jonesi): U.S. Geological Survey data release, https://doi.org/10.5066/F7FT8J5T.
Barber, L.B., Weber, A.K., LeBlanc, D.R., Hull, R.B., Sunderland, E.M., and Vecitis, C.D., 2017, Poly- and perfluoroalkyl substances in contaminated groundwater, Cape Cod, Massachusetts, 2014-2015 (ver. 1.1, March 24, 2017): U.S. Geological Survey data release, https://doi.org/10.5066/F7Z899KT.
For USGS data residing on non-USGS Federal servers, please consult your Bureau Approving Official for guidance.
For Outside Journal Publications
Most peer-reviewed journals will assign the DOI to articles using their own DOI prefix and registration process.
Example outside journal publication (No action needed to create a DOI):
Estimates of Natural Salinity and Hydrology in a Subtropical Estuarine Ecosystem: Implications for Greater Everglades Restoration Frank E. Marshall, G. Lynn Wingard, Patrick A. Pitts. https://doi.org/10.1007/s12237-014-9783-8
What the U.S. Geological Survey Manual Requires:
The USGS Survey Manual chapter SM 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release requires that data approved for release must be assigned a persistent identifier, specifically a Digital Object Identifier (DOI) for scientific data obtained from the USGS registration agent, and be accompanied by a recommended citation.