Professor *Teddy Seidenfeld* (homepage) visited the Algorithms & Complexity group of the Centrum Wiskunde & Informatica on **3 and 4 July 2014**.
He is an expert in the foundations of probability and statistics.

Peter Grünwald & Erik Quaeghebeur organized a small workshop on the occasion of his visit, the program of which you can find below. Next to one scheduled talk there were a number of discussion sessions.

The time before, between, and after the sessions was used for lunch, coffee breaks, rest, etc.

**Thursday 3 July 2014**(room L240)-
- 11:00–13:00
*Discussion*: Safe probability & non-Bayesian updating (Lead: Peter Grünwald)- 15:00–17:00
*Discussion*: The ‘Monty Hall’ puzzle & scoring rules (Lead: Thijs van Ommen)*Discussion*: The ‘Sleeping Beauty’ puzzle (Opening: Erik Quaeghebeur)

**Friday 4 July 2014**(room L017)-
- 11:00–12:30
*Discussion*: When is it better*not*to be Bayesian? (Lead: Jan-Willem Romeijn; related paper)- 14:30–15:15
*Discussion*: A new theory about old evidence (Lead: Jan-Willem Romeijn; related paper)*Discussion*: Bayesian inconsistency in regression (Lead: Peter Grünwald)- 15:15–16:15
*Talk*: The Effect of exchange rates on statistical decisions (joint work with Mark Schervish and Jay Kadane; slides)Statistical decision theory, whether based on Bayesian principles or other concepts such as minimax or admissibility, relies on minimizing expected loss or maximizing expected utility. Loss and utility functions are generally treated as unit-less numerical measures of value for consequences. Here, we address the issue of the units in which loss and utility are settled and the implications that those units have on the rankings of potential decisions. When multiple currencies are available for paying the loss, one must take explicit account of which currency is used as well as the exchange rates between the various available currencies