What are the chances?
An explication of singlecase chance
Project funded by NWO, the
Dutch organisation for
scientific research
University of Groningen, The Netherlands, 20112016
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 FentonGlynn (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 socalled 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
longstanding 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
JanWillem Romeijn 
Patryk DziuroszSerafinowicz 
Ronnie Hermens 
The leader of the research project is JanWillem Romeijn. He is
professor on a tenuretrack 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
DziuroszSerafinowicz 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.
 Oneday 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, OctoberDecember 2013.
 Inaugural lecture JanWillem 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 DziuroszSerafinowicz 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.
JanWillem 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/s112290140632x, 2015
 "Comorbidity: fact or artefact, with H.M. van Loo,
Theoretical Medicine and Bioethics 36(1), pp. 4160, 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):6875, 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
prioradapted 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 DziuroszSerafinowicz
 "Maximum Relative Entropy Updating and the Value of
Learning'', Entropy, 17(3), pp. 11461164, 2015.
 Divergent
LevelRelative Chances and the General Principle, manuscript.
 Are
Humean Chances Formally Adequate?, manuscript.
 Review of Williamson's "In Defence of Objective
Bayesianism", International Studies in the Philosophy of Science
26(3):348351, 2012.
 Common
Cause Abduction, Filozofia Nauki 20(4):5+, 2012.
Ronnie Hermens
 ConwayKochen and the Finite Precision Loophole,
Foundations of Physics 44(10):10381048, 2014.
 Placing Probabilities of Conditionals in Context, The
Review of Symbolic Logic 7(3):415438, 2014.
 Speakable
in Quantum Mechanics: Babbling on, Electronic Proceedings in
Theoretical Computer Science 158:5364, 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):32653286, 2013.
 Weakly Intuitionistic Quantum Logic, Studia Logica
101(5):901913, 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.
JanWillem 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", keynote 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 Subfamily
Problem" at the Conference on Novel Predictions, University of
Duesseldorf, February 2011.
Patryk DziuroszSerafinowicz
 "Chance and Resiliency'' at OZSW Graduate Conference,
Nijmegen, 2930 April  1 May 2015.
 "Comments
on Measuring Accuracy of Uncertain Doxastic States in ManyValued
Logical Systems by Pavel Janda'' at Entia et Nomina Conference,
Kraków, 911 September 2015.
 "Chance and Resiliency'' at Entia et Nomina
Conference, Kraków, 911 September 2015.
 "A
ResiliencyBased Approach to Chance" at the European Philosophy of
Science Association Conference (EPSA15), Duesseldorf, 2326 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", HerfstSymposium 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 JanWillem
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 singlecase chance

