What are the chances?
  An explication of single-case chance

Project funded by NWO, the Dutch organisation for scientific research
University of Groningen, The Netherlands, 2011-2016

 

 

CHANCE ENCOUNTER: CLOSING WORKSHOP

On June 23 and 24 we will hold a closing workshop for the project. The workshop happens right after the Formal Epistemology Workshop, which is also funded by the Chance project. Speakers at the final Chance Encounter are Adam Bales (Cambridge), Patryk Dziurosz (Groningen), Nina Emery (Brown), Luke Fenton-Glynn (UCL), Malcolm Forster (Madison), Roman Frigg (LSE), Ronnie Hermens (Oxford), Aidan Lyon (Maryland / Munich), Mauricio Suarez (Madrid), Jan Sprenger (TiLPS). The programme and abstracts can be found here.

 

THE PROJECT

The concept of probability is of utmost importance to science: many scientific claims are expressed in terms of probability and uncertainty, and almost all methods in the sciences rely on probability and statistics. In many of these applications, the probabilities express chances: they do not express a personal opinion or a degree of belief about events in the world, but rather an objective characteristic of the events themselves. But what are these chances in the world? How do they hang together with the, often deterministic, mechanisms underlying the events? And can we indeed determine these chances by applying statistical methods?

This research aims to explicate chance as a characteristic of events. The focal point for the project is the so-called reference class problem. For instance, if smokers have a chance of 10% to live over 70 years, and vegetarians have a chance of 80%, then what are the chances for a smoking vegetarian? The key idea of the proposal is that only the chances associated with irreducible, or in other words unrefinable, descriptions are correct for the events. The resulting concept of chance provides a basis for calling particular ascriptions of chance correct, even if other descriptions lead to different chances for the event, or to complete determination.

The project throws new light on a long-standing philosophical debate. Moreover, the new concept of chance will motivate us to reconsider and reappraise various statistical methods. It will deepen our understanding of statistical model selection and the nature of simplicity, trading on the idea that model selection guides us to the correct chances. Furthermore it will clarify the role of chance in causal modelling, trading on the idea that changes to the chances effected by experiment are in some sense real. This will eventually improve our insight into, and thus the application of, the statistical methods at hand.

 

PEOPLE


Jan-Willem Romeijn
Patryk Dziurosz-Serafinowicz
Ronnie Hermens

The leader of the research project is Jan-Willem Romeijn. He is professor on a tenure-track at the Faculty of Philosophy of the University of Groningen, where he teaches philosophy of science. His research interests include scientific method, the foundations of statistics, inductive logic, and causal modelling.

Patryk Dziurosz-Serafinowicz is a PhD student at the Faculty of Philosophy of the University of Groningen. He holds a PhD in law, MPhil in Philosophy and MPhil in Law, all obtained from the Jagiellonian University in Krakow. His research interests include philosophy of probability, Bayesian epistemology, abductive reasoning, and philosophy of law.

Ronnie Hermens is a PhD student at the Faculty of Philosophy of the University of Groningen. His research focuses on the nature of probability in theories of physics. Further interests include the philsophy of mathematics and physics.

 

EVENTS

Events are listed if they are organised by project members or partly funded by the project.

  • Formal epistemology workshop 2016, with numerous talks on probability theory in epistemology.
  • Chance encounter with Roger Cooke and Aidan Lyon on expert opinions and climate modelling, October 2015.
  • Workshop with Charlotte Werndl, Simon Friederich, and Pablo Acuna, January 2015.
  • Chance encounter with Sam Fletcher and Peter Grünwald on the likelihood principle, April 2015. 
  • One-day workshops with Erik Nyberg, Frank Zenker, and Alex Broadbent, 2015.
  • Workshop on chance and the principal principle with Jason Konek and Christian Wallmann, September 2014.
  • Visits of Christian Wallmann (Salzburg) and Marta Sznajder (LMU Munich), from August until November 2014.
  • Research visit from Prof. Dr. J. B. M. Uffink (University of Minnesota, USA), June 2014.
  • Workshop on chance and explanation with Michael Strevens and Victor Gijsbers, June 2014.
  • Workshop on deterministic chance with Aidan Lyon and Christian List, January 2014.
  • Research visit to the University of Oxford by Ronnie Hermens, October-December 2013.
  • Inaugural lecture Jan-Willem Romeijn, July 2013.
  • Research visit from Prof. Dr. J. B. M. Uffink (University of Minnesota, USA), June 2013.
  • Workshop on the Frontiers of Rationality and Decision, August 2012. Have a look at the site or read the review in the The Reasoner 6(10), written by Patryk Dziurosz-Serafinowicz and Ronnie Hermens.
  • Workshop on radical uncertainty at the Munich Centre for Mathematical Philosophy, January 2012.
  • Guest lecture on model selection by Kevin Kelly, January 2012.
  • Conference on foundations and applications of model selection entitled All Models are Wrong, in collaboration with Ernst Wit and Edwin van den Heuvel, March 2011.

 

RESEARCH PAPERS

For full lists of manuscripts and publications we refer to the websites of the project members. The following is a list of publications directly relevant to the project's topic.

Jan-Willem Romeijn

  • "Uncertainty in Computational Archaeology", with H. Peeters, in Springer Series in Theoretical Archaeology, to appear.
  • "Psychiatric comorbidity does not only depend on diagnostic thresholds: an illustration with major depressive disorder and generalized anxiety disorder", Depression and Anxiety, DOI 10.1002/da.22453, 2015
  • "A New Theory about Old Evidence", with S. Wenmackers, Synthese, DOI 10.1007/s11229-014-0632-x, 2015
  • "Comorbidity: fact or artefact, with H.M. van Loo, Theoretical Medicine and Bioethics 36(1), pp. 41-60, 2015
  • "Radical Uncertainty", with O. Roy, special issue of Erkenntnis, 2014.
  • "The philosophy of Bayes' factors", with R.D. Morey and J.N. Rouder, Journal of Mathematical Psychology, to appear 2015.
  • "Psychiatric comorbidity and causal disease models", with H.M. van Loo, P. de Jonge, R.A. Schoevers, Preventive Medicine, 57(6), pp. 748Ð752.
  • "Abducted by Bayesians", Journal of Applied Logic, 11(4), pp. 430Ð439, 2013.
  • "Philosophy of Statistics", lemma in the Stanford Encyclopedia of Philosophy, 2014.
  • "The Humble Bayesian", with R. D. Morey and J. N. Rouder, British Journal of Mathematical and Statistical Psychology, 66(1):68-75, 2013.
  • Editor for special issue on "All Models are wrong", with E. Wit and E. van den Heuvel, Statistica Neerlandica, 66(3), 2012.
  • "Philosophy of Statistics", lemma in the Stanford Encyclopedia of Philosophy, to appear.
  • "One size does not fit all: derivation of a prior-adapted BIC", with R. van de Schoot and H. Hoijtink, in Probabilities, Laws, and Structures, ed. by D. Dieks, W. Gonzales, S. Hartmann, F. Stadler, T. Uebel, and M. Weber. Berlin: Springer, 2012.

Patryk Dziurosz-Serafinowicz

Ronnie Hermens

  • Conway-Kochen and the Finite Precision Loophole, Foundations of Physics 44(10):1038-1048, 2014.
  • Placing Probabilities of Conditionals in Context, The Review of Symbolic Logic 7(3):415-438, 2014.
  • Speakable in Quantum Mechanics: Babbling on, Electronic Proceedings in Theoretical Computer Science 158:53-64, 2014 (Proceedings of the 9th Workshop on Quantum Physics and Logic 2012).
  • The Measurement Problem is Your Problem too, New Directions in the Philosophy of Science (Conference proceedings), Springer, 2014.
  • Speakable in Quantum Mechanics, Synthese 190(15):3265-3286, 2013.
  • Weakly Intuitionistic Quantum Logic, Studia Logica 101(5):901-913, 2013.
  • Two Problems in the Reduction of Thermodynamics to Statistical Mechanics, manuscript.

 

PRESENTATIONS

For full lists of talks, see the web sites of the project members. The following concerns selected talks with material directly relevant to the project's topic.

Jan-Willem Romeijn

  • "Subjectivity in Evidence: Three studies in Bayesian Model Evaluation", Department of Philosophy, University of Padua, Italy, 2015.
  • "How to do things with frequentism", lecture for the Institute of Philosophy, University of London, UK, 2015.
  • "Statistics and Belief: how to judge if you must", APES seminar, University of Amsterdam.
  • "Reductionism and objective chance", talk at the OZSW conference, VU Amsterdam.
  • "What are the chances?", research seminar at the Department of Philosophy of the University of Maryland at College Park, and at the University of Amsterdam in 2014, and at the University of Salzburg in 2015.
  • "Comorbidity in Psychiatry", invited talk at the Philosophy Department of the Universities of Cape Town and Johannesburg
  • "Kansen voor het individu", presentation at meeting of various healthcare stakeholders (Zorginstituut, Zorgverzekeraars Nederland, Orde van Medisch Specialisten, etc.), June 2014
  • "Schnorr randomness and Autonomous Chance", talk at the occasion of Michael Strevens' visit to Groningen, June
  • "Comorbidity in Psychiatry", invited talk at Philosophy Departments of the Universities of Cape Town and Johannesburg, March 2014
  • "Frequentism as formal semantics", key-note lecture at a conference on Inductive Logic and Confirmation, Paris campus of the University of Kent, October 2013, and MCMP seminar at the LMU Munich, December 2013
  • "Implicit complexity" at the EPSA conference 2013, Helsinki University, August 2013. An earlier version was given at a research seminar in Gent University, June 2013
  • "Epistemic Statistics" at the Autonomous University of Madrid, February 2013. An earlier version of this talk was given at the EIPE seminar, Erasmus University Rotterdam, November 2012
  • "Belief Dynamics for Conditionals" with Ronnie Hermens at the conference on historical counterfactuals at the University of Bristol, August 2012.
  • "Implicit Complexity" at the Conference of the Spanish Society for Logic and Philosophy of Science, July 2012.
  • "Verrassing!" at a symposium on new epistemology of the Dutch Philosophy of Science association (NVWF), June 2012.
  • "De Onvermijdelijkheid van Theorie" at the Center for Psychiatry of the University of Groningen, May 2012.
  • "Frequencies, Chances and Undefinable Sets" at the Combined research seminar for the Munich Centre for Mathematical Philosophy and the Statistics Department of the Ludwig Maximilians University, July 2011.
  • "Specificity, Accommodation and the Sub-family Problem" at the Conference on Novel Predictions, University of Duesseldorf, February 2011.

Patryk Dziurosz-Serafinowicz

  • "Chance and Resiliency'' at OZSW Graduate Conference, Nijmegen, 29-30 April - 1 May 2015.
  • "Comments on Measuring Accuracy of Uncertain Doxastic States in Many-Valued Logical Systems by Pavel Janda'' at Entia et Nomina Conference, Kraków, 9-11 September 2015.
  • "Chance and Resiliency'' at Entia et Nomina Conference, Kraków, 9-11 September 2015.
  • "A Resiliency-Based Approach to Chance" at the European Philosophy of Science Association Conference (EPSA15), Duesseldorf, 23-26 September 2015.
  • "Maximum Entropy Updating and the Value of Learning'', Fribourg's Colloquium, Fribourg, October 28, 2015.
  • ÒDivergent Conditional Chances, Admissibility, and ResiliencyÓ at the GroLog research seminar, Groningen, June 2014.
  • ÒThe General Principle and Conflicting Conditional Chances, at the 8th European Congress of Analytic Philosophy, Bucharest, August 2014.
  • "Are Humean Chances Formally Adequate?" at the Fourth Conference of the European Philosophy of Science Association, Helsinki, August 2013.
  • "Are Humean Chances Formally Adequate?" at the Graduate Conference in Theoretical Philosophy at the University of Groningen, April 2013.
  • "Are Humean Chances Formally Adequate?" at the First International Conference of the German Society for Philosophy of Science, Leibniz University Hannover, March 2013.
  • "Are David Lewis’ Humean Chances Probabilities?" at the Erasmus Graduate Conference in Philosophy of Science, Rotterdam, March 2012.

Ronnnie Hermens

  • "Quantum Logic & Quantum Probability: An Empiricist Approach", at a conference on Quantum Computation, Quantum Information, and the Exact Sciences, Munich, Germany, 2015 January 31.
  • "Indeterminisme en Waarschijnlijkheid In de Quantamechanica", Herfst-Symposium Nederlandse Vereniging voor WetenschapsFilosofie, Groningen, The Netherlands, 2014 November 26.
  • "Philosophy of quantum probability: An empiricist approach", at the 2nd International Summer School in Philosophy of Physics: Probabilities in Physics, Saig, Germany, 2014 July 22.
  • "On the ontological status of quantum probabilities" at the Graduate Conference in Theoretical Philosophy in Amsterdam, May 2014
  • "On The Structure of Quantum Probabilities" at the 2nd International Summer School in Philosophy of Physics: Probabilities in Physics, July 2014
  • "Placing Probabilities of Conditionals in Context" at the Formal Epistemology Festival in Toronto, June 2013.
  • "Reduction in Gibbsian Statistical Mechanics" at the Graduate Conference in Theoretical Philosophy at the University of Groningen, April 2013.
  • "Belief Dynamics for Conditionals" with Jan-Willem Romeijn at the conference on historical counterfactuals at the University of Bristol, August 2012.

 

WHY ZEBRA?

The yearly survival rate of zebra depends on a large number of things. Biological data may present the following statistics: 70% of female zebra survive each year, 80% of zebra aged over five years do, and for zebra with recent offspring the rate of survival is 90%. Now consider a female zebra of twelve years that had offspring in the past season. What is the chance that this particular zebra survives? Is there any such chance of survival for this individual zebra? Questions like these are at the heart of the research project.

 

What are the chances? An explication of single-case chance