# Presentation: 366548

## Associating Persistent Identifiers between Trustworthy Repositories

- Arnold Rots, Alberto Accomazzi, Günther EichhornHarvard-Smithsonian Center for Astrophysics

- Rots et al., Persistent Identifiers

- 2007-04-26

## Data and Literature

- The Astrophysics Data Centers Executive Council (ADEC) developed, at the request of Astrophysics Data System (ADS), a standard that allows published papers to link to the archived datasets presented or used in those papers – and vice versa

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifiers

- ADEC established a standard for assigning identifiers to datasets:
- Unique
- Provide persistent access to datasets
- But also:
- Low buy-in

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifier Spec

- URI
- Part of International Virtual Observatory Alliance’s (IVOA) identifier space:
-        ivo://

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifier Spec

- URI
- Part of International Virtual Observatory Alliance’s (IVOA) identifier space
- Issued under ADS authority:
-        ivo://ADS/

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifier Spec

- URI
- Part of International Virtual Observatory Alliance’s (IVOA) identifier space
- Issued under ADS authority
- Published by a recognized observatory:
-        ivo://ADS/Sa.CXO#

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifier Spec

- URI
- Part of International Virtual Observatory Alliance’s (IVOA) identifier space
- Issued under ADS authority
- Published by a recognized observatory
- Which may add its own designations:
-        ivo://ADS/Sa.CXO#obs/8547

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifier Requirement

- Needs to lead the user to the dataset
- I.e., should translate to a URL that *allows* the user to retrieve a DIP:
- It may be an interface, as long as the datasets are marked
- The DIP may be an image, a tarfile, etc.
- The URI should be supported in perpetuity, though the URL may change

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifiers & Version

- The Dataset Identifier is not required to point to the same data version in perpetuity – that’s left to the repository
- In the Chandra Data Archive we have some 15,000 distinct datasets of 7,000 unique observations
- We have yet to receive the first request for a dataset that is not default

- Rots et al., Persistent Identifiers

- 2007-04-26

## Dataset Identifiers & TDRs

- The ADEC/ADS Dataset Identifier also satisfies requirement B2.5 in the OCLC/CRL *“Trustworthy Repositories Audit & Certification: Criteria and Checklist”*
- If our data centers were to pursue TRAC certification, they pass B2.5 automatically

- Rots et al., Persistent Identifiers

- 2007-04-26

## Datasets and Literature

- It’s a simple matter of associating Dataset Identifiers with “Bibcodes”
- Agreement with the AAS journal editors that authors can insert the Dataset Identifiers into manuscripts
- Identifiers are embedded in the data
- Harvesting Bibcode-Identifier pairs

- Rots et al., Persistent Identifiers

- 2007-04-26

## Further Generalization

- Bibcode can be generalized to a Dataset Identifier:		ivo://ADS/ads#2007AJ...
- Now the harvesting becomes collecting pairs of Dataset Identifiers
- This provides a mechanism to associate datasets between repositories, e.g., Great Observatory Joint Observations

- Rots et al., Persistent Identifiers

- 2007-04-26

## Summary

- ADEC Dataset Identifiers:
- ... are easy to implement because of decentralized definition
- ... are successful in linking literature and data (but: burden on authors)
- ... qualify under TRAC B2.6
- ... allow linking of related observations
- ... enjoy all but guaranteed persistence for data published by NASA data centers

- Rots et al., Persistent Identifiers

- 2007-04-26