
404The wisdom of collective grading and the effects of epistemic and semantic diversityTheory and Decision 85 (1): 99116. 2018.A computer simulation is used to study collective judgements that an expert panel reaches on the basis of qualitative probability judgements contributed by individual members. The simulated panel displays a strong and robust crowd wisdom effect. The panel's performance is better when members contribute precise probability estimates instead of qualitative judgements, but not by much. Surprisingly, it doesn't always hurt for panel members to interpret the probability expressions differently. Indee…Read more

96Vague CredenceSynthese 194 (10): 39313954. 2017.It is natural to think of precise probabilities as being special cases of imprecise probabilities, the special case being when one’s lower and upper probabilities are equal. I argue, however, that it is better to think of the two models as representing two different aspects of our credences, which are often vague to some degree. I show that by combining the two models into one model, and understanding that model as a model of vague credence, a natural interpretation arises that suggests a hypoth…Read more

38Philosophy of ProbabliltyIn Fritz Allhoff (ed.), Philosophies of the Sciences: A Guide, Wileyblackwell. 2010.In the philosophy of probability there are two central questions we are concerned with. The first is: what is the correct formal theory of probability? Orthodoxy has it that Kolmogorov’s axioms are the correct axioms of probability. However, we shall see that there are good reasons to consider alternative axiom systems. The second central question is: what do probability statements mean? Are probabilities “out there”, in the world as frequencies, propensities, or some other objective feature of …Read more

204Why are Normal Distributions Normal?British Journal for the Philosophy of Science 65 (3): 621649. 2014.It is usually supposed that the central limit theorem explains why various quantities we find in nature are approximately normally distributed—people's heights, examination grades, snowflake sizes, and so on. This sort of explanation is found in many textbooks across the sciences, particularly in biology, economics, and sociology. Contrary to this received wisdom, I argue that in many cases we are not justified in claiming that the central limit theorem explains why a particular quantity is norm…Read more

377How common standards can diminish collective intelligence: a computational studyJournal of Evaluation in Clinical Practice 22 (4): 483489. 2016.Making good decisions depends on having accurate information – quickly, and in a form in which it can be readily communicated and acted upon. Two features of medical practice can help: deliberation in groups and the use of scores and grades in evaluation. We study the contributions of these features using a multiagent computer simulation of groups of physicians. One might expect individual differences in members’ grading standards to reduce the capacity of the group to discover the facts on whi…Read more

229Deterministic Probability: Neither chance nor credenceSynthese 182 (3): 413432. 2011.Some have argued that chance and determinism are compatible in order to account for the objectivity of probabilities in theories that are compatible with determinism, like Classical Statistical Mechanics (CSM) and Evolutionary Theory (ET). Contrarily, some have argued that chance and determinism are incompatible, and so such probabilities are subjective. In this paper, I argue that both of these positions are unsatisfactory. I argue that the probabilities of theories like CSM and ET are not chan…Read more

578The explanatory power of phase spacesPhilosophia Mathematica 16 (2): 227243. 2008.David Malament argued that Hartry Field's nominalisation program is unlikely to be able to deal with nonspacetime theories such as phasespace theories. We give a specific example of such a phasespace theory and argue that this presentation of the theory delivers explanations that are not available in the classical presentation of the theory. This suggests that even if phasespace theories can be nominalised, the resulting theory will not have the explanatory power of the original. Phasespac…Read more

148Mathematical Explanations Of Empirical Facts, And Mathematical RealismAustralasian Journal of Philosophy 90 (3): 559578. 2012.A main thread of the debate over mathematical realism has come down to whether mathematics does explanatory work of its own in some of our best scientific explanations of empirical facts. Realists argue that it does; antirealists argue that it doesn't. Part of this debate depends on how mathematics might be able to do explanatory work in an explanation. Everyone agrees that it's not enough that there merely be some mathematics in the explanation. Antirealists claim there is nothing mathematics…Read more

University of Maryland, College ParkRegular Faculty
College Park, Maryland, United States of America
Areas of Specialization
Philosophy of Mathematics 
Philosophy of Probability 
General Philosophy of Science 