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REVIEW 5 major objections 6 minor 31 references

FAIR Digital Objects for the Realization of Globally Aligned Data Spaces

T0 review · 5 major / 6 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read FAIR Digital Objects can be pinned down by eight formal expressions, giving data spaces a common machine-actionable baseline without changing the data spaces themselves.

desk verdict Useful conceptual consolidation of FDO ideas with concrete examples, but the formal core is broken as written and needs major revision before it can serve as a validation baseline. read the letter →

arxiv 2411.18663 v1 pith:BUVT4TDC submitted 2024-11-27 cs.DB

classification cs.DB
keywords FAIRDigitalObjectsKernelInformationProfiledataspacesmachineactionabilitytypedattributesPIDgraphinteroperabilityprinciples
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper sets out to make FAIR Digital Objects implementable and checkable in practice. Its central claim is that a small set of formal expressions, equations (1) through (8), can serve as a common baseline for what an FDO is and how it behaves, replacing today's diverse and partly contradictory specifications. The model says every FDO wraps exactly one digital resource in one information record that instantiates exactly one Kernel Information Profile, carries six mandatory typed attributes plus a persistent identifier, exposes a set of operations tied to those attributes, and can link to other FDOs through PID triples. If the model is adopted, data spaces can expose a uniform, machine-actionable layer without modifying their native storage or metadata. The paper supports this by demonstrating the model on two cross-domain use cases and by checking existing FDO-style Handle records against it.

What carries the argument

The load-bearing object is the Kernel Information Profile (KIP): a canonical set of typed attributes, each key identified by a persistent identifier rather than a human-readable name, that describes the bit sequence a digital resource consists of. The machinery has three parts: (1) KIP instantiation—every FDO gets exactly one information record from exactly one profile (Eqs. (1)–(2)); (2) a mandatory attribute layer—six generic attributes that every valid record must contain, together with a Handle PID (Eq. (3)); and (3) the association graph—typed attribute key-value pairs that trigger operations (Eqs. (4)–(6)) and serve as predicates for PID triples forming the FDO graph (Eqs. (7)–(8)). This triad turns the FAIR slogan 'machine-actionable' into a checkable condition: if the record conforms, a machine can validate integrity, evaluate licensing, fetch the resource, and traverse relationships without domain-specific knowledge.

What would settle it

Find any registered FDO-style record that omits one of the six mandatory attributes yet still lets a machine evaluate its license, validate its checksum, fetch its bit sequence, and traverse its relationships; such a record would refute the claim that $A_m$ is the minimal necessary set. A second falsifier is a compound resource, such as a dataset with multiple schemas, that cannot be captured by a single information record without violating Eq. (2).

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Extended reading notes

Core claim

The paper's claim, stated on its own terms, is that a FAIR Digital Object is not a loose idea but a precisely testable structure. An FDO $f$ must instantiate exactly one Kernel Information Profile $p$ (Eqs. (1)–(2)), producing a single information record $R_f$; that record must contain a nonempty minimum set $A_m$ of six typed attributes—profile reference, license, checksum, digital resource location, creation date, and resource type—and receive a persistent identifier (Eq. (3)). Operations are associated with the FDO through key-value pairs in the record (Eq. (4)), with bit-sequence access via a location attribute (Eq. (5)) and applicability to metadata or bit sequence (Eq. (6)). Entity relationships let referencing attributes point to other entities, so PID triples $\langle i_{\mathrm{sub}}, i_{\mathrm{pre}}, i_{\mathrm{obj}}\rangle$ form a directed FDO graph $G$ (Eqs. (7)–(8)). The paper then argues that this structure meets the FAIR criteria, especially machine actionability, and uses it to assess three project-specific Handle records, none of which satisfies the model completely.

Load-bearing premise

The load-bearing assumption is that every digital resource can be represented by exactly one information record instantiating exactly one Kernel Information Profile, and that the six mandatory attributes are the necessary and sufficient minimum for machine actionability.

Editorial extensions

If this is right

  • Any community can validate an FDO mechanically by checking Eqs. (1)–(3): exactly one KIP, six mandatory typed attributes, and a resolvable persistent identifier.
  • A standard set of generic operations—license evaluation, checksum validation, related-resource traversal, and resource retrieval—becomes available for every conforming FDO, because all four are anchored in the typed attributes of the record.
  • Organizations can offer a common abstraction layer over their data spaces without migrating or modifying their storage systems, metadata schemas, or access protocols.
  • The comparative analysis provides a concrete conformance test: current FDO-style records from other projects are at best partially compliant, so adopting the baseline would measurably increase interoperability.
  • Persistent information records can outlive the resources they describe, so reproducibility data remain available even after a bit sequence is gone.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The paper leaves the rules for extending Kernel Information Profiles and for associating operations to attributes as future work; if those rules are standardized as a registry of typed-attribute PIDs and operation names, the model's validation can be automated end to end.
  • Because the graph in Eq. (8) is structurally RDF-with-PIDs, mature graph and Semantic Web tooling could be applied to an FDO space without designing new infrastructure—an implication the paper gestures at but does not develop.
  • The six-attribute minimum set is a design axiom. A direct extension would be an empirical study collecting many machine-actionable resource records to see whether any attribute in $A_m$ is ever unused, or whether a seventh attribute, for example provenance, is needed in practice.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

5 major / 6 minor

Summary. The paper proposes a formalized data model for FAIR Digital Objects (FDOs), expressed in equations (1)–(8) covering KIP instantiation, mandatory attributes, associated operations, entity relationships, and a PID-triple graph. It presents two implementation examples (energy research and digital humanities), compares three existing Handle records (PIDINST, DARIAH, DiSSCo) against the model in Table II, and gives a FAIR-criteria compliance analysis in Section III-C. The central claim is that this assertion set provides a rigorous, common baseline for implementing and validating FDOs across data spaces, thereby enabling globally aligned FAIR data spaces.

Significance. The motivation is strong: the FDO landscape is fragmented, and a concrete, checkable model could serve as a valuable conformance baseline. The paper contributes practical artifacts—a registered Helmholtz KIP, a resolvable PID record, and a comparison with external FDO-related projects—which are useful for the community. If the formalization were actually rigorous and the validation procedure reproducible, the paper would be an important milestone. However, as written, the mathematical core does not support the 'rigorously formalized' claim; the formal expressions contain syntactic errors and under-specified semantics, and the FAIR analysis is a self-assessment without a reproducible method. The significance therefore lies more in the concrete demonstrations and the comparative discussion than in the formal system itself.

major comments (5)
  1. [Section III-A, Eq. (2)] Equation (2) is not a well-formed first-order formula: the variables p and p' in the consequent are outside the scope of the existential quantifiers in the antecedent, leaving them free. The intended uniqueness condition should be written as ∀f∈F ∀p∈P ∀p'∈P (((Instantiate(f,p)=Rf) ∧ (Instantiate(f,p')=Rf)) ⇒ p=p'). Under any charitable reading of the printed formula, it collapses to a statement no stronger than Eq. (1), so the model cannot exclude an FDO whose record instantiates two distinct KIPs. Consequently, the 'Instantiates one KIP' row of Table II, which cites Eqs. (1,2), has no formal basis, and the paper's headline contribution—a rigorous validation baseline—is not delivered by the formal system as written.
  2. [Section III-A, Eq. (4)] Equation (4), ∀f∈F ∃k∈K ∃o∈O : Associated(k,o)=Of, asserts the existence of a single pair (k,o) whose association equals the entire set Of. This conflates an association relation with the set of all operations for the FDO and does not state that the operations in Of are exactly those associated with some key-value pair. The intended meaning appears to be something like Of = {o∈O | ∃k∈K : Associated(k,o)}, but as written the equation is too weak and not checkable. This undermines the formal basis for the operation-association claims in Section IV-B and in Table II row 4.
  3. [Section III-B, Eq. (7)] Equation (7), '∀f∈F : K′_f → E′, k′_f 7→ e′', is not a well-formed expression in the notation used elsewhere in the paper. The variable e′ is unbound, the arrow is ambiguous between a function and a relation, and no domain or codomain is specified for k′_f. A rigorous version would need to introduce a relation, e.g., ∀f∈F, ∀k′∈K′_f, ∃e′∈E′ : RefersTo(k′,e′), with RefersTo defined from the typed attribute values. As printed, Eq. (7) cannot be used in the comparative analysis or in the definition of the PID-triple graph that follows.
  4. [Section III-C] The FAIR compliance analysis is a bulleted list of claims that map model features to FAIR and FAIR4RS criteria without an evaluation method or external assessment framework. There are no concrete indicators, no reproducible test procedure, and no use of tools such as F-UJI or the RDA FAIR Data Maturity Model. The arguments are self-assessments that assume the model's own terms (e.g., 'FDOs are accessible by a communication protocol' and 'information records are persistently preserved through the policies of the PID system') rather than demonstrating compliance. This weakens the paper's claim that the model 'fulfills FAIR criteria,' and the section should either be substantially expanded with a defined methodological framework or repositioned as a design rationale rather than a compliance analysis.
  5. [Section IV-C, Table II] The comparative evaluation in Table II purports to check external Handle records against expressions (1)–(8). Since several of these expressions are ill-formed or under-specified (notably Eqs. (2), (4), and (7)), the entries 'yes', 'no', and 'partially' are not reproducible from the formal model. The authors should specify an operational checking procedure for each equation—for example, how one determines 'instantiates one KIP' or 'attributes are typed on the record level' from a concrete Handle record—so that the table can serve as the claimed validation baseline.
minor comments (6)
  1. [Section III-A, text after Fig. 2] The phrase 'such that Ap ⊆ p ∈ P' is syntactically unclear; it should be stated as 'Ap is a subset of the attribute set of p' or similar, since p is a profile and not a set of attributes.
  2. [Section III-A, Eq. (1)] The symbol Rf is used before it is defined as the information record for FDO f; the authors should introduce Rf explicitly, e.g., 'let Rf denote the information record of f'.
  3. [Section III-A, Eq. (5)] The bit sequence s is an unbound variable in Eq. (5); the formula should quantify over s or define it as a function of f, e.g., ∀os∈Os ∃kacc∈R : Access(kacc) = bitseq(f).
  4. [Section III-A, Eq. (3)] The uniqueness expression ∃!i is not given a scope or a sort; it would be clearer to write ∃!i∈I : Assign(i, Rf) = Rf_reg.
  5. [Section III-C, third bullet] The claim that 'FDO information records are persistently preserved through the policies of the PID system' is an assumption about the underlying infrastructure, not a property of the model; this should be explicitly separated from model-inherent properties.
  6. [Table I] The table header contains a typographical issue ('Obli-gatory'); also, the table would benefit from stating which attributes correspond to the mandatory set Am defined in Section III-A.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the formal model is an externally anchored normative baseline, and the comparative and FAIR assessments do not reduce to fitted inputs or self-citation.

full rationale

The paper's central derivation chain is the definition of a formal FDO model via expressions (1)-(8), followed by a FAIR-criteria mapping and a compatibility comparison with externally documented Handle records. The model is not fitted to any outcome: the mandatory attribute set Am and the KIP concept are adopted from RDA and the external FDO literature, not derived from the model's own outputs. Table II evaluates three independent records (PIDINST, DARIAH, DiSSCo) against the paper's expressions; those records are external to the paper, and the model expressions are not adjusted on the basis of the comparison, so the evaluation is not a self-prediction. The FAIR-compliance section is an interpretive mapping of model features to the FAIR criteria, not an empirical prediction that could be circular in the sense of being equivalent to its inputs. Self-citations such as the example datasets or the Helmholtz KIP are used only as illustrative material and do not carry the formal argument. One internal issue should be noted as a correctness concern rather than circularity: equation (2), as printed, has a quantifier-scope ambiguity that prevents it from cleanly expressing the intended KIP uniqueness property. This undermines the rigor of the formalization, but it does not make the model's comparison or FAIR assessment circular. The paper's central claim, if repaired, would still be an independent formal proposal evaluated against external records.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

The central claim rests on design axioms (unique KIP per FDO, sufficiency of the six mandatory attributes, PIDs as predicates) and a self-assessment of FAIR compliance. None of these is independently grounded or fitted to data.

assumptions (4)
  • ad hoc to paper Each FDO instantiates exactly one Kernel Information Profile, which determines its information record (Eq. 1-2).
    This uniqueness constraint is asserted as a design axiom rather than derived from requirements or observed implementations; it becomes the basis for validation and comparison in Table II.
  • ad hoc to paper The six mandatory attributes Am (profile reference, license, checksum, location, creation date, resource type) are necessary and sufficient for machine actionability (Section III-A, Eq. 3).
    Adopted from RDA recommendations without proof or empirical evidence that these six suffice for the claimed operations.
  • domain assumption PIDs of typed attribute keys can act as semantic predicates in a graph without further semantics (Section III-B, Eq. 7-8).
    Assumes a PID key with a semantic definition is enough for machines to interpret the relationship; no formal semantics or reasoning rules are provided.
  • domain assumption The mapping from FDO characteristics to FAIR criteria in Section III-C is a valid compliance assessment.
    The authors enumerate 'cf. FAIR:...' statements with no formal method or accepted tool; existing tools like F-UJI are explicitly not used.

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Cite this review

Pith. "Pith review of FAIR Digital Objects for the Realization of Globally Aligned Data Spaces." pith.science (2026). https://pith.science/paper/BUVT4TDC

@misc{pith2026241118663,
  author       = {Pith},
  title        = {Pith review of: FAIR Digital Objects for the Realization of Globally Aligned Data Spaces},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/BUVT4TDC}},
  note         = {Machine review of arXiv:2411.18663}
}
read the original abstract

The FAIR principles are globally accepted guidelines for improved data management practices with the potential to align data spaces on a global scale. In practice, this is only marginally achieved through the different ways in which organizations interpret and implement these principles. The concept of FAIR Digital Objects provides a way to realize a domain-independent abstraction layer that could solve this problem, but its specifications are currently diverse, contradictory, and restricted to semantic models. In this work, we introduce a rigorously formalized data model with a set of assertions using formal expressions to provide a common baseline for the implementation of FAIR Digital Objects. The model defines how these objects enable machine-actionable decisions based on the principles of abstraction, encapsulation, and entity relationship to fulfill FAIR criteria for the digital resources they represent. We provide implementation examples in the context of two use cases and explain how our model can facilitate the (re)use of data across domains. We also compare how our model assertions are met by FAIR Digital Objects as they have been described in other projects. Finally, we discuss our results' adoption criteria, limitations, and perspectives in the big data context. Overall, our work represents an important milestone for various communities working towards globally aligned data spaces through FAIRification.

Figures

Figures reproduced from arXiv: 2411.18663 by the authors.

Figure 1
Figure 1. The current state of partially aligned FAIRified data spaces is [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. The semantic FDO Data Model specification depicting the relation [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. The conceptual model of PID triples based on the FDO’s entity [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: An exemplary FDO according to the formalized data model that [PITH_FULL_IMAGE:figures/full_fig_p006_4.png]
Figure 5
Figure 5. Figure 5: Resuming the illustration of a high-level abstraction layer around [PITH_FULL_IMAGE:figures/full_fig_p007_5.png]

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Reference graph

Works this paper leans on

31 extracted references · 31 canonical work pages

  1. [1]

    The FAIR Guiding Principles for scientific data management and stewardship,

    M. D. Wilkinson, M. Dumontier, I. J. Aalbersberg, G. Appleton, M. Axton, A. Baak et al., “The FAIR Guiding Principles for scientific data management and stewardship,” Sci. Data, vol. 3, no. 1, p. 160018, 2016

  2. [2]

    Digital Objects as Drivers towards Convergence in Data Infrastructures,

    P. Wittenburg and G. O. Strawn, “Digital Objects as Drivers towards Convergence in Data Infrastructures,”

  3. [3]

    Interoperability and FAIRness through a novel combination of Web technologies,

    M. D. Wilkinson, R. Verborgh, L. O. B. d. S. Santos, T. Clark, M. A. Swertz, F. D. L. Kelpin et al. , “Interoperability and FAIRness through a novel combination of Web technologies,” PeerJ Comput. Sci. , vol. 3, p. e110, 2017

  4. [4]

    Curry, S

    E. Curry, S. Scerri, and T. Tuikka, Data Spaces: Design, Deployment, and Future Directions. Cham: Springer International Publishing, 2022, pp. 1–17

  5. [5]

    Delgado, Interoperability Effect in Big Data

    J. Delgado, Interoperability Effect in Big Data . Cham: Springer International Publishing, 2021, pp. 875–901

  6. [6]

    FAIR for AI: An interdisciplinary and international community building perspective,

    E. A. Huerta, B. Blaiszik, L. C. Brinson, K. E. Bouchard, D. Diaz, C. Doglioni et al., “FAIR for AI: An interdisciplinary and international community building perspective,” Sci. Data, vol. 10, no. 1, p. 487, Jul. 2023

  7. [7]

    An automated solution for measuring the progress toward FAIR research data,

    A. Devaraju and R. Huber, “An automated solution for measuring the progress toward FAIR research data,” Patterns, vol. 2, no. 11, p. 100370, 2021

  8. [8]

    FAIR Principles: Interpretations and Implementation Considerations,

    A. Jacobsen, R. de Miranda Azevedo, N. Juty, D. Batista, S. Coles, R. Cornet et al. , “FAIR Principles: Interpretations and Implementation Considerations,” Data Intell., vol. 2, no. 1-2, pp. 10–29, Jan. 2020

Show all 31 references
  1. [9]

    FAIR Digital Objects for Sci- ence: From Data Pieces to Actionable Knowledge Units,

    K. Smedt, D. Koureas, and P. Wittenburg, “FAIR Digital Objects for Sci- ence: From Data Pieces to Actionable Knowledge Units,” Publications, vol. 8, p. 21, 2020

  2. [10]

    Introducing the FAIR Principles for research software,

    M. Barker, N. P. Chue Hong, D. S. Katz, A.-L. Lamprecht, C. Martinez- Ortiz, F. Psomopoulos et al. , “Introducing the FAIR Principles for research software,” Sci. Data, vol. 9, no. 1, p. 622, Oct. 2022

  3. [11]

    Working Towards Understanding the Role of FAIR for Machine Learning,

    D. S. Katz, F. Psomopoulos, and L. J. Castro, “Working Towards Understanding the Role of FAIR for Machine Learning,” in Proc. 2nd Workshop on Data and Research Objects Management for Linked Open Science, Virtual Conference, 2021, pp. 1–6

  4. [12]

    Automated schema extraction for PID information types,

    U. Schwardmann, “Automated schema extraction for PID information types,” in Proc. IEEE International Conference on Big Data (Big Data) , Dec. 2016, pp. 3036–3044

  5. [13]

    A framework for distributed digital object services,

    R. Kahn and R. Wilensky, “A framework for distributed digital object services,” Int. J. Digit. Libr. , vol. 6, no. 2, pp. 115–123, 2006

  6. [14]

    Digital Object Interface Protocol Specification,

    DONA Foundation, “Digital Object Interface Protocol Specification,”

  7. [15]

    Connected Research: The Potential of the PID Graph,

    H. Cousijn, R. Braukmann, M. Fenner, C. Ferguson, R. van Horik, R. Lammey et al. , “Connected Research: The Potential of the PID Graph,” Patterns, vol. 2, no. 1, p. 100180, Jan. 2021

  8. [16]

    Data Type Registries: A Research Data Alliance Working Group,

    D. Broeder and L. Lannom, “Data Type Registries: A Research Data Alliance Working Group,” D-Lib Mag., vol. 20, 2014

  9. [17]

    Digital Objects – FAIR Digital Objects: Which Services Are Required?

    U. Schwardmann, “Digital Objects – FAIR Digital Objects: Which Services Are Required?” Data Sci. J. , vol. 19, p. 15, 2020

  10. [18]

    Schultes and P

    E. Schultes and P. Wittenburg, FAIR Principles and Digital Objects: Accelerating Convergence on a Data Infrastructure . Cham: Springer International Publishing, 2019, pp. 3–16

  11. [19]

    Commission, D.-G

    E. Commission, D.-G. for Research, Innovation, O. Corcho, M. Eriksson, K. Kurowski et al. , EOSC interoperability framework – Report from the EOSC Executive Board Working Groups FAIR and Architecture . Publications Office, 2021

  12. [20]

    The genera Chrysilla and Phintelloides revisited with the description of a new species (Araneae, Salticidae) using digital specimen DOIs and nanopublica- tions,

    C. Deeleman-Reinhold, W. Addink, and J. Miller, “The genera Chrysilla and Phintelloides revisited with the description of a new species (Araneae, Salticidae) using digital specimen DOIs and nanopublica- tions,” Biodivers. Data J. , vol. 12, p. e129438, Sep. 2024

  13. [21]

    Assessing the FAIR Digital Object Framework for Global Biodiversity Research,

    S. Islam, J. Beach, E. Ellwood, J. Fortes, L. Lannom, G. Nelson et al., “Assessing the FAIR Digital Object Framework for Global Biodiversity Research,” Res. Ideas Outcomes , vol. 9, Sep. 2023

  14. [22]

    Thermal Bridges on Building Rooftops,

    Z. Mayer, J. Kahn, M. G ¨otz, Y . Hou, T. Beiersd ¨orfer, N. Blumenr ¨ohr et al., “Thermal Bridges on Building Rooftops,” Sci. Data, vol. 10, no. 1, p. 268, 2023

  15. [23]

    Towards a Conceptual Model for the FAIR Digital Object Framework,

    L. O. Bonino da Silva Santos, T. P. Sales, C. M. Fonseca, and G. Guizzardi, “Towards a Conceptual Model for the FAIR Digital Object Framework,” in Formal Ontology in Information Systems . IOS Press, 2023, pp. 227–241

  16. [24]

    Evaluating FAIR Digital Object and Linked Data as distributed object systems,

    S. Soiland-Reyes, C. Goble, and P. Groth, “Evaluating FAIR Digital Object and Linked Data as distributed object systems,” PeerJ Comput. Sci., vol. 10, p. e1781, Apr. 2024

  17. [25]

    Deep learning approaches to building rooftop thermal bridge detection from aerial images,

    Z. Mayer, J. Kahn, Y . Hou, M. G ¨otz, R. V olk, and F. Schultmann, “Deep learning approaches to building rooftop thermal bridge detection from aerial images,” Autom. Constr., vol. 146, p. 104690, 2023

  18. [26]

    A Gold Standard Benchmark Dataset for Digital Humanities,

    F. Kraus, N. Blumenr ¨ohr, G. G ¨otzelmann, D. Tonne, and A. Streit, “A Gold Standard Benchmark Dataset for Digital Humanities,” in Proc. of the 19th International Workshop on Ontology Matching , Baltimore, USA, in press

  19. [27]

    Realizing FAIR Digital Objects for the German Helmholtz Association of Research Centres,

    T. Jejkal, A. Pfeil, J. Schweikert, A. Pirogov, P. Barranco, F. Krebs et al., “Realizing FAIR Digital Objects for the German Helmholtz Association of Research Centres,” Res. Ideas Outcomes, vol. 8, p. e94758, Oct. 2022

  20. [28]

    Persistent identification of instruments,

    M. Stocker, L. Darroch, R. Krahl, T. Habermann, A. Devaraju, U. Schwardmann et al., “Persistent identification of instruments,” Data Sci. J., vol. 19, p. 18, May 2020

  21. [29]

    How FDO attributes can support machine- and human-readability? - a description along three examples,

    U. Schwardmann and T. K ´alm´an, “How FDO attributes can support machine- and human-readability? - a description along three examples,” Res. Ideas Outcomes , vol. 9, p. e108737, Oct. 2023

  22. [2018]

    Available: https://www.dona.net/sites/default/files/ 2018-11/DOIPv2Spec 1.pdf

    [Online]. Available: https://www.dona.net/sites/default/files/ 2018-11/DOIPv2Spec 1.pdf

  23. [2019]

    Available: https://doi.org/10.23728/B2SHARE

    [Online]. Available: https://doi.org/10.23728/B2SHARE. B605D85809CA45679B110719B6C6CB11

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Reviewed August 12, 2026 · model on record in the stance chip above.