Legal Theory

My work on modelling legal argument naturally has made me interested in philosophy of law and legal theory. I occasionally present my work before audiences from these fields.

One of my research interests in legal theory is rational legal proof.

• In 2007 I co-organised an IVR-07 Workshop on Reasoning about Legal Evidence with Floris Bex and Bart Verheij. This workshop led to an edited volume on Legal Evidence and Proof: Statistics, Stories, Logic, published in Ashgate's Applied legal Philosophy Series, January 2009.

• Also in 2007, I was the program chair of a Conference on Graphic and Visual Representations of Evidence and Inference in Legal Settings (conference brochure), organised by Peter Tillers at the Benjamin N. Cardozo School of Law in New York (USA). This event resulted in a special issue of Law, Probability and Risk, Vol. 7, Issue 1-4.

• Between 2012 and 2018 I was a co-organiser of and lecturer in the annual Summer School on Law and Logic at the European University Institute in Florence, Italy.

• In 2015 Floris Bex, Anne Ruth Mackor and I co-organised a Zif Workshop on Models of Rational Proof in Criminal Law at the Center for Interdisciplinary Research of the University of Bielefeld (Germany). This eventually led to a special issue of Topics in Cognitive Science on Models of Rational Proof in Criminal Law, in 2020. In this special issue six groups of researchers apply their favourite reasoning method(s) to the case files of an actual murder case.

• I was an expert witness in two court cases in 2015 (ECLI:NL:GHDHA:2015:2859, a murder case) and 2016 (ECLI:NL:GHSHE:2016:5165, a serial-arson case). In both cases my task was to comment on a report by an expert witness for the prosecution in which the entire case was analysed with Bayesian probability theory. In my two papers with Ronald Meester in the list below I reflect on this experience.

• I have written several papers for Dutch law journals on the practical application in court of models of rational legal proof, including Bayesian models:
  • H. Prakken, Strafrechtelijk bewijzen: met Bayes of met verhalen? Of is er een derde weg?. Expertise en Recht 2014-1, 4-19. (In Dutch. English title: Criminal legal proof: with Bayes or with stories? Or is there a third way?) [PDF]
  • H. Prakken, Een reactie op H.W.J. de Groot: `Moord op de A73'. Expertise en Recht 2016-2, 63-70. (In Dutch. English title: Comments on H.W.J. de Groot: `Murder on the A73'.) [PDF]
  • H. Prakken & R. Meester, Bayesiaanse analyses van complexe strafzaken door deskundigen. Betrouwbaar en zo ja: nuttig? Expertise en Recht 2017-5, 185-197 (in Dutch). English title: 'Bayesian analyses of complex criminal cases: reliable and if so, useful?') [PDF] (version 20 oktober 2017)
  • H. Prakken & R. Meester, Reactie op Alkemades weerwoord. Expertise en Recht 2018-1, 41-43 (In Dutch. English title: 'Response to Alkemades reply.) [PDF]
  • H. Prakken, Kansoordelen door deskundigen: over 'logisch' rapporteren en wat daarbij mis kan gaan. Ars Aequi 67 (2018), 740-747. (In Dutch. English title: 'Probabilistic assessments by experts: about 'logical' reporting and what can go wrong with it'.) [PDF]
  • A.R. Mackor & H. Prakken, Over voor juristen (on)begrijpelijke rapportages door deskundigen Expertise en Recht 2026-5, to appear (in Dutch). English title: 'About for layers (in)comprehensible expert reports'. [PDF]

Associations, interest groups, resources ...

• VWR - Dutch Association for Philosophy of Law
• IVR - International Association for Philosophy of Law and Social Philosophy
• The North Sea Group. A research community on legal evidence and proof.