Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Reply to “Comment on ‘Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection' ”

Patrick J. Daley, Kevin J. Resch, Robert W. Spekkens

Published Jan 16, 2025• 0 citations
Publisher

Abstract

Our article described an experiment that adjudicates between different causal accounts of Bell inequality violations by a comparison of their predictive power, finding that certain types of models that are structurally radical but parametrically conservative---of which a class of superdeterministic models are an example---overfit the data relative to models that are structurally conservative but parametrically radical in the sense of endorsing an intrinsically quantum generalization of the framework of causal modeling. In their comment [Phys. Rev. A 109, 026201 (2024)], Hance and Hossenfelder argue that we have misrepresented the purpose of superdeterministic models. We here dispute this claim by recalling the different classes of superdeterministic models we defined in our article and our conclusions regarding which of these are disfavored by our experimental results. Their confusion on this point seems to have arisen in part from the fact that we characterized superdeterministic models within a causal modeling framework and from the fact that we referred to this framework as ``classical'' in order to contrast it with an intrinsically quantum alternative. In this Reply, therefore, we take the opportunity to clarify these points. They also claim that if one is adjudicating between a pair of models, where one model can account for strictly more operational statistics than the other, the first model will tend to overfit the data relative to the second. Because this model inclusion relation can arise for pairs of models in a reductionist hierarchy, they conclude that overfitting should not be taken as evidence against the first model. We point out here that, contrary to this claim, one does not expect overfitting to arise generically in cases of model inclusion, so that it is indeed sometimes appropriate to consider overfitting as a criterion for adjudicating between such models.

DOI
10.1103/physreva.111.016201

Related papers

Reply to "Comment on 'Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection'"

Daley, Patrick, Kevin J. Resch, Robert W. Spekkens

Our article described an experiment that adjudicates between different causal accounts of Bell inequality violations by a comparison of their predictive power, finding that certain types of models that are structurally radical but parametrically conservative, of which a class of superdeterministic models are an example, overfit the data relative to models that are structurally conservative but parametrically radical in the sense of endorsing an intrinsically quantum generalization of the framework of causal modelling. In their comment (arXiv:2206.10619), Hance and Hossenfelder argue that we have misrepresented the purpose of superdeterministic models. We here dispute this claim by recalling the different classes of superdeterministic models we defined in our article and our conclusions regarding which of these are disfavoured by our experimental results. Their confusion on this point seems to have arisen in part from the fact that we characterized superdeterministic models within a causal modelling framework and from the fact that we referred to this framework as "classical" in order to contrast it with an intrinsically quantum alternative. In this reply, therefore, we take the opportunity to clarify these points. They also claim that if one is adjudicating between a pair of models, where one model can account for strictly more operational statistics than the other, the first model will tend to overfit the data relative to the second. Because this model inclusion relation can arise for pairs of models in a reductionist heirarchy, they conclude that overfitting should not be taken as evidence against the first model. We point out here that, contrary to this claim, one does not expect overfitting to arise generically in cases of model inclusion, so that it is indeed sometimes appropriate to consider overfitting as a criterion for adjudicating between such models.

arXiv:2412.02829•Dec 3, 2024•0 citations

Comment on “Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection”

Jonte R. Hance, Sabine Hossenfelder

In a recent paper [Phys. Rev. A 105, 042220 (2022)], Daley et al. claim that some superdeterministic models are disfavored relative to standard quantum mechanics because such models overfit the statistics of a Bell-type experiment which the authors conducted. We add to the discussion by providing additional context about how few superdeterministic models fall into the category they analyze, and by emphasizing that overfitting, while better as a measure of fine-tuning than other measures given in the literature, does not necessarily indicate a model is universally bad.

arXiv:2206.10619•Physical Review A•Feb 14, 2024•2 citations

Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection

Patrick J. Daley, Kevin J. Resch, Robert W. Spekkens

Bell famously showed that it was possible to adjudicate between quantum theory and classical hidden-variable theories on experimental grounds rather than merely philosophical ones. These days, there is a new dispute, regarding the question of how to causally account for Bell correlations, with some suggesting a quantum common cause, others a classical superluminal influence. Here, the authors propose a way to move beyond philosophical disputes by comparing the predictive power of different models. They show that the classical models actually tend to overfit Bell test data.

arXiv:2108.00053•Physical Review A•Apr 29, 2022•7 citations

Reply to "Comment on 'Why interference phenomena do not capture the essence of quantum theory' "

Lorenzo Catani, Matthew Leifer, David Schmid +1 more

Our article [arXiv:2111.13727(2021)] argues that the phenomenology of interference that is traditionally regarded as problematic does not, in fact, capture the essence of quantum theory -- contrary to the claims of Feynman and many others. It does so by demonstrating the existence of a physical theory, which we term the "toy field theory", that reproduces this phenomenology but which does not sacrifice the classical worldview. In their Comment [arXiv:2204.01768(2022)], Hance and Hossenfelder dispute our claim. Correcting mistaken claims found therein and responding to their criticisms provides us with an opportunity to further clarify some of the ideas in our article.

arXiv:2207.11791•Jul 24, 2022•1 citation

Reply to superdeterminists on the hidden-variable formulation of Invariant-set theory

Indrajit Sen

In a recent article (arXiv:2108.08144), Hance, Hossenfelder and Palmer have advanced arguments claiming to show that the analysis of Invariant-set theory in a hidden-variable setting (arXiv:2107.04761) is wrong. We explain here why these arguments are incorrect, and involve misunderstandings of the hidden-variable model in question and Bell's notion of local causality.

arXiv:2109.11109•Sep 23, 2021•0 citations

Reply to “Comment on ‘Nonlocality claims are inconsistent with Hilbert-space quantum mechanics’ ”

Robert B. Griffiths

In Phys. Rev. A 101, 022117 (2020), it was argued that Bell inequalities are based on classical not quantum physics, and, hence, their violation in experiments provides no support for the claimed existence of peculiar nonlocal and superluminal influences in the real (quantum) world. This Reply to Lambare's Comment, Phys. Rev. A 104, 066201 (2021), on that paper seeks to clarify some issues related to the correct use of Hilbert space quantum mechanics for identifying the microscopic causes of later macroscopic measurement outcomes, a matter not properly addressed by Bell, who used classical hidden variables in place of the Hilbert subspaces (equivalently, their projectors) employed by von Neumann in Mathematical Foundations of Quantum Mechanics.

arXiv:2106.09824•Physical Review A•Dec 20, 2021•11 citations
Our article described an experiment that adjudicates between different causal accounts of Bell inequality violations by a comparison of their predictive power, finding that certain types of models that are structurally radical but parametrically conservative---of which a class of superdeterministic models are an example---overfit the data relative to models that are structurally conservative but parametrically radical in the sense of endorsing an intrinsically quantum generalization of the framework of causal modeling. In their comment [Phys. Rev. A 109, 026201 (2024)], Hance and Hossenfelder argue that we have misrepresented the purpose of superdeterministic models. We here dispute this claim by recalling the different classes of superdeterministic models we defined in our article and our conclusions regarding which of these are disfavored by our experimental results. Their confusion on this point seems to have arisen in part from the fact that we characterized superdeterministic models within a causal modeling framework and from the fact that we referred to this framework as ``classical'' in order to contrast it with an intrinsically quantum alternative. In this Reply, therefore, we take the opportunity to clarify these points. They also claim that if one is adjudicating between a pair of models, where one model can account for strictly more operational statistics than the other, the first model will tend to overfit the data relative to the second. Because this model inclusion relation can arise for pairs of models in a reductionist hierarchy, they conclude that overfitting should not be taken as evidence against the first model. We point out here that, contrary to this claim, one does not expect overfitting to arise generically in cases of model inclusion, so that it is indeed sometimes appropriate to consider overfitting as a criterion for adjudicating between such models.
Our article described an experiment that adjudicates between different causal accounts of Bell inequality violations by a comparison of their predictive power, finding that certain types of models that are structurally radical but parametrically conservative, of which a class of superdeterministic models are an example, overfit the data relative to models that are structurally conservative but parametrically radical in the sense of endorsing an intrinsically quantum generalization of the framework of causal modelling. In their comment (arXiv:2206.10619), Hance and Hossenfelder argue that we have misrepresented the purpose of superdeterministic models. We here dispute this claim by recalling the different classes of superdeterministic models we defined in our article and our conclusions regarding which of these are disfavoured by our experimental results. Their confusion on this point seems to have arisen in part from the fact that we characterized superdeterministic models within a causal modelling framework and from the fact that we referred to this framework as "classical" in order to contrast it with an intrinsically quantum alternative. In this reply, therefore, we take the opportunity to clarify these points. They also claim that if one is adjudicating between a pair of models, where one model can account for strictly more operational statistics than the other, the first model will tend to overfit the data relative to the second. Because this model inclusion relation can arise for pairs of models in a reductionist heirarchy, they conclude that overfitting should not be taken as evidence against the first model. We point out here that, contrary to this claim, one does not expect overfitting to arise generically in cases of model inclusion, so that it is indeed sometimes appropriate to consider overfitting as a criterion for adjudicating between such models.
In a recent paper [Phys. Rev. A 105, 042220 (2022)], Daley et al. claim that some superdeterministic models are disfavored relative to standard quantum mechanics because such models overfit the statistics of a Bell-type experiment which the authors conducted. We add to the discussion by providing additional context about how few superdeterministic models fall into the category they analyze, and by emphasizing that overfitting, while better as a measure of fine-tuning than other measures given in the literature, does not necessarily indicate a model is universally bad.
Bell famously showed that it was possible to adjudicate between quantum theory and classical hidden-variable theories on experimental grounds rather than merely philosophical ones. These days, there is a new dispute, regarding the question of how to causally account for Bell correlations, with some suggesting a quantum common cause, others a classical superluminal influence. Here, the authors propose a way to move beyond philosophical disputes by comparing the predictive power of different models. They show that the classical models actually tend to overfit Bell test data.
Our article [arXiv:2111.13727(2021)] argues that the phenomenology of interference that is traditionally regarded as problematic does not, in fact, capture the essence of quantum theory -- contrary to the claims of Feynman and many others. It does so by demonstrating the existence of a physical theory, which we term the "toy field theory", that reproduces this phenomenology but which does not sacrifice the classical worldview. In their Comment [arXiv:2204.01768(2022)], Hance and Hossenfelder dispute our claim. Correcting mistaken claims found therein and responding to their criticisms provides us with an opportunity to further clarify some of the ideas in our article.
In Phys. Rev. A 101, 022117 (2020), it was argued that Bell inequalities are based on classical not quantum physics, and, hence, their violation in experiments provides no support for the claimed existence of peculiar nonlocal and superluminal influences in the real (quantum) world. This Reply to Lambare's Comment, Phys. Rev. A 104, 066201 (2021), on that paper seeks to clarify some issues related to the correct use of Hilbert space quantum mechanics for identifying the microscopic causes of later macroscopic measurement outcomes, a matter not properly addressed by Bell, who used classical hidden variables in place of the Hilbert subspaces (equivalently, their projectors) employed by von Neumann in Mathematical Foundations of Quantum Mechanics.