The sameAs Problem: A Survey on Identity Management in the Web of Data

Fatiha Sa\"is; Frank van Harmelen; Joe Raad; Nathalie Pernelle; Wouter Beek

arxiv: 1907.10528 · v1 · pith:4LFWT37Fnew · submitted 2019-07-24 · 💻 cs.DB · cs.AI

The sameAs Problem: A Survey on Identity Management in the Web of Data

Joe Raad , Nathalie Pernelle , Fatiha Sa\"is , Wouter Beek , Frank van Harmelen This is my paper

Pith reviewed 2026-05-24 16:22 UTC · model grok-4.3

classification 💻 cs.DB cs.AI

keywords sameAs problemidentity managementWeb of Datalinked dataowl:sameAsknowledge graphsdata integrationsurvey

0 comments

The pith

Incorrect sameAs links disrupt data reuse across the Web of Data.

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

This survey investigates the sameAs problem in decentralized knowledge graphs, where multiple names for one entity require owl:sameAs statements to connect overlapping data sources. These statements enable useful deductions for reuse, yet incorrect applications produce wide effects in a global system. The authors review prior work that has already shown identity is broken, examine weaknesses in existing solutions, and identify open challenges ahead. A sympathetic reader would care because reliable identity links are required for any effective data integration or reasoning over the Web of Data.

Core claim

The paper claims that identity management in the Web of Data is broken. Several earlier studies have established problems with sameAs statements. This survey maps the current state of solutions, draws out their main weaknesses, and lists the open challenges that remain to be solved.

What carries the argument

The owl:sameAs statement, which asserts that two names denote the same entity and thereby links data for reuse.

If this is right

Knowledge graphs from different sources cannot be merged reliably without correct identity links.
Deductive systems built on the Web of Data will propagate errors from faulty sameAs statements.
Data reuse across the Web of Data remains limited until identity weaknesses are resolved.
Future identity solutions must address the specific weaknesses identified in current approaches.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

Applications such as federated query engines or linked-data browsers may need explicit handling of uncertain identity rather than assuming sameAs is reliable.
Similar identity management difficulties could arise in other decentralized data environments outside the Web of Data.
Verification or qualification mechanisms for identity statements may be required in addition to the existing binary sameAs relation.

Load-bearing premise

The body of prior work reviewed accurately represents the prevalence and nature of the sameAs problem today.

What would settle it

A large-scale audit of public datasets that finds most sameAs statements to be correct and shows no measurable negative effects on downstream data applications.

read the original abstract

In a decentralised knowledge representation system such as the Web of Data, it is common and indeed desirable for different knowledge graphs to overlap. Whenever multiple names are used to denote the same thing, owl:sameAs statements are needed in order to link the data and foster reuse. Whilst the deductive value of such identity statements can be extremely useful in enhancing various knowledge-based systems, incorrect use of identity can have wide-ranging effects in a global knowledge space like the Web of Data. With several works already proven that identity in the Web is broken, this survey investigates the current state of this "sameAs problem". An open discussion highlights the main weaknesses suffered by solutions in the literature, and draws open challenges to be faced in the future.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

This is a standard literature survey on the sameAs problem with no new results or techniques.

read the letter

This paper is a survey on identity management in the Web of Data, focused on owl:sameAs links. It collects existing work showing that these links are frequently incorrect and discusses the downstream effects on linked data reuse. No new dataset, proof, or method appears in the abstract or description. The main contribution is organization: it reviews demonstrations that identity is broken, then examines solutions and their weaknesses before listing open challenges. That synthesis is the useful part. It brings scattered observations into one place and flags recurring problems with current approaches to identity. The tone is straightforward about the limits of existing fixes. The soft spots are typical for a survey. Its claims rest on the accuracy and coverage of the cited literature rather than fresh evidence, and the abstract gives no detail on how papers were selected or how exhaustive the review is. That makes it harder to judge whether important counter-examples or recent work were missed. There are no mathematical claims or fitted parameters to check, so no circularity or fitting issues arise. The central point about wide-ranging effects from bad identity statements is carried by the prior works it cites. This paper is for people already working in Semantic Web, linked data, or knowledge graphs who want a consolidated starting point on the identity problem. A reader outside that subfield will not find much to apply elsewhere. It deserves peer review because a well-executed survey can clarify the state of a narrow but persistent issue and guide follow-on work, even without original results. The authors appear to engage directly with the cited evidence rather than overclaiming.

Referee Report

1 major / 1 minor

Summary. This survey investigates the 'sameAs problem' in the Web of Data: the use of owl:sameAs to link overlapping knowledge graphs, the deductive utility of correct identity statements, and the wide-ranging effects of incorrect identity assertions. It reviews prior works demonstrating that identity management on the Web is broken, discusses main weaknesses of existing solutions, and identifies open challenges for future work.

Significance. If the survey faithfully represents the cited literature, it consolidates knowledge on a practically important issue for decentralized Semantic Web systems and can usefully direct attention to open challenges in identity management.

major comments (1)

[Introduction / Survey methodology] The manuscript does not describe the search strategy, inclusion/exclusion criteria, or temporal scope used to select the reviewed works. This information is required to evaluate whether the cited body of literature accurately represents the current state of the sameAs problem (as asserted in the abstract and introduction).

minor comments (1)

[Abstract] The abstract states that 'several works already proven that identity in the Web is broken' but does not cite those works; the introduction should provide explicit references at this point.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for this constructive comment on our survey. We agree that a clear description of the literature selection process is necessary for a survey paper and will incorporate it in the revision.

read point-by-point responses

Referee: [Introduction / Survey methodology] The manuscript does not describe the search strategy, inclusion/exclusion criteria, or temporal scope used to select the reviewed works. This information is required to evaluate whether the cited body of literature accurately represents the current state of the sameAs problem (as asserted in the abstract and introduction).

Authors: We acknowledge the omission. The original manuscript focused on synthesizing known issues and challenges rather than on the systematic review protocol. In the revised version we will add a new subsection (likely in Section 1 or as a dedicated 'Survey Methodology' section) that explicitly states the search strategy (e.g., Google Scholar, DBLP, Semantic Web venues), the keywords and Boolean queries employed, the temporal scope (papers up to mid-2019), and the inclusion/exclusion criteria applied to ensure the cited works represent the state of the sameAs problem. revision: yes

Circularity Check

0 steps flagged

No significant circularity: survey of external literature

full rationale

This is a literature survey whose central claim (incorrect identity statements can have wide-ranging effects) is supported by citations to prior external demonstrations that 'identity in the Web is broken.' No new equations, fitted parameters, predictions, uniqueness theorems, or ansatzes are introduced by the authors. The load-bearing condition is accurate representation of the cited body of work, which is external to the present paper and therefore does not reduce to self-definition or self-citation chains within this manuscript. No circular steps are present.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Survey paper; no free parameters, axioms, or invented entities are introduced by the authors.

pith-pipeline@v0.9.0 · 5661 in / 842 out tokens · 17389 ms · 2026-05-24T16:22:41.138559+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Foundation/AbsoluteFloorClosure.lean absolute_floor_iff_bare_distinguishability echoes

?

echoes
ECHOES: this paper passage has the same mathematical shape or conceptual pattern as the Recognition theorem, but is not a direct formal dependency.

identity is reﬂexive, symmetrical and transitive also follows from Leibniz’s Law... a = b → (∀ψ∈Ψ)(ψ(a) = ψ(b))

What do these tags mean?

matches: The paper's claim is directly supported by a theorem in the formal canon.
supports: The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends: The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses: The paper appears to rely on the theorem as machinery.
contradicts: The paper's claim conflicts with a theorem or certificate in the canon.
unclear: Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

32 extracted references · 32 canonical work pages

[1]

Batchelor, C

[]Batchelor et al., 2014 C. Batchelor, C. Brenninkmeijer, C. Chichester, M. Davies, D. Digles, I. Dunlop, C. Evelo, A. Gaulton, C. Goble, A. Gray, et al. Scientiﬁc lenses to support multiple views over linked chemistry data. In ISWC, pages 98–113. Springer,

work page 2014
[2]

[]Beek et al., 2016 W . Beek, S. Schlobach, and F. van Harmelen. A contextualised semantics for owl: sameas. In ISWC, pages 405–419. Springer,

work page 2016
[3]

[]Beek et al., 2018 W . Beek, J. Raad, J. Wielemaker, and F. van Harmelen. sameas. cc: The closure of 500m owl: sameas statements. In ESWC, pages 65–80. Springer,

work page 2018
[4]

Bouquet, F

[]Bouquet et al., 2003 P . Bouquet, F. Giunchiglia, F. V an Harmelen, L. Seraﬁni, and H. Stuckenschmidt. C-owl: Contextualizing ontologies. In ISWC, pages 164–179. Springer,

work page 2003
[5]

Bouquet, H

[]Bouquet et al., 2007 P . Bouquet, H. Stoermer, and D. Gi- acomuzzi. OKKAM: enabling a web of entities. In I3, volume 249 of CEUR W orkshop Proceedings,

work page 2007
[6]

CudreMauroux, P

[]CudreMauroux et al., 2009 P . CudreMauroux, P . Haghani, M. Jost, K. Aberer, and H. De Meer. idmesh: graph-based disambiguation of linked data. In WWW, pages 591–600. ACM,

work page 2009
[7]

Cuzzola, E

[]Cuzzola et al., 2015 J. Cuzzola, E. Bagheri, and J. Jo- vanovic. Filtering inaccurate entity co-references on the linked open data. In DEXA, pages 128–143. Springer,

work page 2015
[8]

[]de Melo, 2013 G. de Melo. Not quite the same: Identity constraints for the web of linked data. In Twenty-Seventh AAAI Conference on Artiﬁcial Intelligence ,

work page 2013
[9]

Euzenat and P

[]Euzenat and Shvaiko, 2013 J. Euzenat and P . Shvaiko. On- tology Matching, 2nd Edition . Springer,

work page 2013
[10]

Fern´ andez, W

[]Fern´ andezet al., 2017 J. Fern´ andez, W . Beek, M. Mart´ ınez-Prieto, and M. Arias. Lod-a-lot. In ISWC, pages 75–83. Springer,

work page 2017
[11]

Ferrara, A

[]Ferrara et al., 2013 A. Ferrara, A. Nikolov, and F. Scharffe. Data linking for the semantic web. Semantic W eb: On- tology and Knowledge Base Enabled T ools, Services, and Applications, 169:326,

work page 2013
[12]

[]Geach, 1967 P .T. Geach. Identity. Review of Metaphysics , 21:3–12,

work page 1967
[13]

Glaser, A

[]Glaser et al., 2009 H. Glaser, A. Jaffri, and I. Millard. Managing co-reference on the semantic web. In WWW W orkshop on Linked Data on the W eb,

work page 2009
[14]

Grant and V

[]Grant and Subrahmanian, 1995 J. Grant and V . S. Subrah- manian. Reasoning in inconsistent knowledge bases. IEEE Trans. Knowl. Data Eng., 7(1):177–189,

work page 1995
[15]

Gu´ eret, P

[]Gu´ eretet al., 2012 C. Gu´ eret, P . Groth, C. Stadler, and J. Lehmann. Assessing linked data mappings using net- work measures. In ESWC, pages 87–102. Springer,

work page 2012
[16]

[]Guha, 1991 R. Guha. Contexts: a formalization and some applications, volume

work page 1991
[17]

Halpin, P

[]Halpin et al., 2010 H. Halpin, P . J Hayes, J. McCusker, D. McGuinness, and H. Thompson. When owl:sameAs isn’t the same: An analysis of identity in Linked Data. In ISWC, pages 305–320. Springer,

work page 2010
[18]

Sense and reference on the web (doctoral dissertation)

[]Halpin, 2010 Harry Halpin. Sense and reference on the web (doctoral dissertation). University of Edinburgh,

work page 2010
[19]

Hogan, A

[]Hogan et al., 2012 A. Hogan, A. Zimmermann, J. Um- brich, A. Polleres, and S. Decker. Scalable and distributed methods for entity matching, consolidation and disam- biguation over linked data corpora. W eb Semantics Jour- nal, 10:76–110,

work page 2012
[20]

Idrissou, R

[]Idrissou et al., 2017 A. Idrissou, R. Hoekstra, F. van Harmelen, A. Khalili, and P . van den Besselaar. Is my: sameas the same as your: sameas?: Lenticular lenses for context-speciﬁc identity. In K-CAP, page

work page 2017
[21]

[]Kripke, 1972 S. Kripke. Naming and necessity. In Seman- tics of natural language , pages 253–355. Springer,

work page 1972
[22]

[]Lewis, 1986 D. Lewis. On the plurality of worlds. Oxford, 14:43,

work page 1986
[23]

Mealling and R Daniel

[]Mealling and Daniel, 1999 M. Mealling and R Daniel. Uri resolution services necessary for urn resolution (rfc 2483 ),

work page 1999
[24]

Nentwig, M

[]Nentwig et al., 2017 M. Nentwig, M. Hartung, A. Ngonga Ngomo, and E. Rahm. A survey of current link discovery frameworks. Semantic W eb, 8(3):419–436,

work page 2017
[25]

[]Nguyen, 2007 N. Nguyen. Advanced methods for inconsis- tent knowledge management. Springer Science & Business Media, Secaucus, NJ, USA,

work page 2007
[26]

Papaleo, N

[]Papaleo et al., 2014 L. Papaleo, N. Pernelle, F. Sa¨ ıs, and C. Dumont. Logical detection of invalid sameas statements in rdf data. In EKAW, pages 373–384. Springer,

work page 2014
[27]

Paulheim

[]Paulheim, 2014 H. Paulheim. Identifying wrong links be- tween datasets by multi-dimensional outlier detection. In W oDOOM, pages 27–38,

work page 2014
[28]

[]Raad et al., 2017 J. Raad, N. Pernelle, and F. Sa¨ ıs. Detec- tion of contextual identity links in a knowledge base. In K-CAP, page

work page 2017
[29]

[]Raad et al., 2018 J. Raad, W . Beek, F. van Harmelen, N. Pernelle, and F. Sa¨ ıs. Detecting erroneous identity links on the web using network metrics. In ISWC, pages 391–

work page 2018
[30]

Schlegel, F

[]Schlegel et al., 2014 K. Schlegel, F. Stegmaier, S. Bayerl, M. Granitzer, and H. Kosch. Balloon fusion: Sparql rewrit- ing based on uniﬁed co-reference information. In Data Engineering W orkshops, pages 254–259. IEEE,

work page 2014
[31]

Entity linking with a knowledge base: Issues, tech- niques, and solutions

[]Shen et al., 2015 Wei Shen, Jianyong Wang, and Jiawei Han. Entity linking with a knowledge base: Issues, tech- niques, and solutions. IEEE Transactions on Knowledge and Data Engineering , 27(2):443–460,

work page 2015
[32]

V aldestilhas, T

[]V aldestilhaset al., 2017 A. V aldestilhas, T. Soru, and A. Ngonga Ngomo. Cedal: time-efﬁcient detection of er- roneous links in large-scale link repositories. In ICWI, pages 106–113. ACM, 2017

work page 2017

[1] [1]

Batchelor, C

[]Batchelor et al., 2014 C. Batchelor, C. Brenninkmeijer, C. Chichester, M. Davies, D. Digles, I. Dunlop, C. Evelo, A. Gaulton, C. Goble, A. Gray, et al. Scientiﬁc lenses to support multiple views over linked chemistry data. In ISWC, pages 98–113. Springer,

work page 2014

[2] [2]

[]Beek et al., 2016 W . Beek, S. Schlobach, and F. van Harmelen. A contextualised semantics for owl: sameas. In ISWC, pages 405–419. Springer,

work page 2016

[3] [3]

[]Beek et al., 2018 W . Beek, J. Raad, J. Wielemaker, and F. van Harmelen. sameas. cc: The closure of 500m owl: sameas statements. In ESWC, pages 65–80. Springer,

work page 2018

[4] [4]

Bouquet, F

[]Bouquet et al., 2003 P . Bouquet, F. Giunchiglia, F. V an Harmelen, L. Seraﬁni, and H. Stuckenschmidt. C-owl: Contextualizing ontologies. In ISWC, pages 164–179. Springer,

work page 2003

[5] [5]

Bouquet, H

[]Bouquet et al., 2007 P . Bouquet, H. Stoermer, and D. Gi- acomuzzi. OKKAM: enabling a web of entities. In I3, volume 249 of CEUR W orkshop Proceedings,

work page 2007

[6] [6]

CudreMauroux, P

[]CudreMauroux et al., 2009 P . CudreMauroux, P . Haghani, M. Jost, K. Aberer, and H. De Meer. idmesh: graph-based disambiguation of linked data. In WWW, pages 591–600. ACM,

work page 2009

[7] [7]

Cuzzola, E

[]Cuzzola et al., 2015 J. Cuzzola, E. Bagheri, and J. Jo- vanovic. Filtering inaccurate entity co-references on the linked open data. In DEXA, pages 128–143. Springer,

work page 2015

[8] [8]

[]de Melo, 2013 G. de Melo. Not quite the same: Identity constraints for the web of linked data. In Twenty-Seventh AAAI Conference on Artiﬁcial Intelligence ,

work page 2013

[9] [9]

Euzenat and P

[]Euzenat and Shvaiko, 2013 J. Euzenat and P . Shvaiko. On- tology Matching, 2nd Edition . Springer,

work page 2013

[10] [10]

Fern´ andez, W

[]Fern´ andezet al., 2017 J. Fern´ andez, W . Beek, M. Mart´ ınez-Prieto, and M. Arias. Lod-a-lot. In ISWC, pages 75–83. Springer,

work page 2017

[11] [11]

Ferrara, A

[]Ferrara et al., 2013 A. Ferrara, A. Nikolov, and F. Scharffe. Data linking for the semantic web. Semantic W eb: On- tology and Knowledge Base Enabled T ools, Services, and Applications, 169:326,

work page 2013

[12] [12]

[]Geach, 1967 P .T. Geach. Identity. Review of Metaphysics , 21:3–12,

work page 1967

[13] [13]

Glaser, A

[]Glaser et al., 2009 H. Glaser, A. Jaffri, and I. Millard. Managing co-reference on the semantic web. In WWW W orkshop on Linked Data on the W eb,

work page 2009

[14] [14]

Grant and V

[]Grant and Subrahmanian, 1995 J. Grant and V . S. Subrah- manian. Reasoning in inconsistent knowledge bases. IEEE Trans. Knowl. Data Eng., 7(1):177–189,

work page 1995

[15] [15]

Gu´ eret, P

[]Gu´ eretet al., 2012 C. Gu´ eret, P . Groth, C. Stadler, and J. Lehmann. Assessing linked data mappings using net- work measures. In ESWC, pages 87–102. Springer,

work page 2012

[16] [16]

[]Guha, 1991 R. Guha. Contexts: a formalization and some applications, volume

work page 1991

[17] [17]

Halpin, P

[]Halpin et al., 2010 H. Halpin, P . J Hayes, J. McCusker, D. McGuinness, and H. Thompson. When owl:sameAs isn’t the same: An analysis of identity in Linked Data. In ISWC, pages 305–320. Springer,

work page 2010

[18] [18]

Sense and reference on the web (doctoral dissertation)

[]Halpin, 2010 Harry Halpin. Sense and reference on the web (doctoral dissertation). University of Edinburgh,

work page 2010

[19] [19]

Hogan, A

[]Hogan et al., 2012 A. Hogan, A. Zimmermann, J. Um- brich, A. Polleres, and S. Decker. Scalable and distributed methods for entity matching, consolidation and disam- biguation over linked data corpora. W eb Semantics Jour- nal, 10:76–110,

work page 2012

[20] [20]

Idrissou, R

[]Idrissou et al., 2017 A. Idrissou, R. Hoekstra, F. van Harmelen, A. Khalili, and P . van den Besselaar. Is my: sameas the same as your: sameas?: Lenticular lenses for context-speciﬁc identity. In K-CAP, page

work page 2017

[21] [21]

[]Kripke, 1972 S. Kripke. Naming and necessity. In Seman- tics of natural language , pages 253–355. Springer,

work page 1972

[22] [22]

[]Lewis, 1986 D. Lewis. On the plurality of worlds. Oxford, 14:43,

work page 1986

[23] [23]

Mealling and R Daniel

[]Mealling and Daniel, 1999 M. Mealling and R Daniel. Uri resolution services necessary for urn resolution (rfc 2483 ),

work page 1999

[24] [24]

Nentwig, M

[]Nentwig et al., 2017 M. Nentwig, M. Hartung, A. Ngonga Ngomo, and E. Rahm. A survey of current link discovery frameworks. Semantic W eb, 8(3):419–436,

work page 2017

[25] [25]

[]Nguyen, 2007 N. Nguyen. Advanced methods for inconsis- tent knowledge management. Springer Science & Business Media, Secaucus, NJ, USA,

work page 2007

[26] [26]

Papaleo, N

[]Papaleo et al., 2014 L. Papaleo, N. Pernelle, F. Sa¨ ıs, and C. Dumont. Logical detection of invalid sameas statements in rdf data. In EKAW, pages 373–384. Springer,

work page 2014

[27] [27]

Paulheim

[]Paulheim, 2014 H. Paulheim. Identifying wrong links be- tween datasets by multi-dimensional outlier detection. In W oDOOM, pages 27–38,

work page 2014

[28] [28]

[]Raad et al., 2017 J. Raad, N. Pernelle, and F. Sa¨ ıs. Detec- tion of contextual identity links in a knowledge base. In K-CAP, page

work page 2017

[29] [29]

[]Raad et al., 2018 J. Raad, W . Beek, F. van Harmelen, N. Pernelle, and F. Sa¨ ıs. Detecting erroneous identity links on the web using network metrics. In ISWC, pages 391–

work page 2018

[30] [30]

Schlegel, F

[]Schlegel et al., 2014 K. Schlegel, F. Stegmaier, S. Bayerl, M. Granitzer, and H. Kosch. Balloon fusion: Sparql rewrit- ing based on uniﬁed co-reference information. In Data Engineering W orkshops, pages 254–259. IEEE,

work page 2014

[31] [31]

Entity linking with a knowledge base: Issues, tech- niques, and solutions

[]Shen et al., 2015 Wei Shen, Jianyong Wang, and Jiawei Han. Entity linking with a knowledge base: Issues, tech- niques, and solutions. IEEE Transactions on Knowledge and Data Engineering , 27(2):443–460,

work page 2015

[32] [32]

V aldestilhas, T

[]V aldestilhaset al., 2017 A. V aldestilhas, T. Soru, and A. Ngonga Ngomo. Cedal: time-efﬁcient detection of er- roneous links in large-scale link repositories. In ICWI, pages 106–113. ACM, 2017

work page 2017