# Workshop "Experimental Pragmatics meets Game Theory"

January 14, 2013, 2-8 p.m.Organizer: Gerhard Jäger (Tübingen)

Recent work on experimental pragmatics by Noah Goodman and co-workers
(Frank & Goodman 2012, Science; Goodman & Stuhlmueller 2012,
CogSci; Bergen, Godman & Levy, 2012; CogSci) has shown a remarkable
convergence with the Iterated Best Response model of game theoretic
pragmatics (Degen & Franke 2012, SemDial; Degen, Franke & Jäger
2012, XPrag; Franke 2009, PhD thesis Amsterdam; Franke 2011, Semantics
& Pragmatics; Franke & Jäger 2012, JoLLI; Jäger & Ebert
2009, Sinn+Bedeutung, Jäger 2012 Handbook Semantics, Jäger to appear, Erkenntnis). The workshop serves to
identify points where these two research traditions agree and where
they differ, and to explore whether a joint agenda for future research
can be developed.

__Invited speakers:__

• Judith Degen (University of Rochester, Department of Brain and Cognitive Sciences)

• Michael Franke (University of Amsterdam, Institute of Logic, Language and Computation)

• Noah Goodman (Stanford University, Department of Psychology)

• Michael Franke (University of Amsterdam, Institute of Logic, Language and Computation)

• Noah Goodman (Stanford University, Department of Psychology)

__Program:__

14:00 - 15:00: Gerhard Jäger, The Iterated Best Response Model of game theoretic pragmatics and its closest relatives

15:15 - 16:15: Judith Degen, Reasoning about Referential Expressions

16:45 - 17:45: Michael Franke, The Use of Quantifiers: Set Size & Typicality

18:15 - 19:15: Noah Goodman, Uncertainty in Pragmatics and Semantics

15:15 - 16:15: Judith Degen, Reasoning about Referential Expressions

16:45 - 17:45: Michael Franke, The Use of Quantifiers: Set Size & Typicality

18:15 - 19:15: Noah Goodman, Uncertainty in Pragmatics and Semantics

__Abstracts:__

**Judith Degen**—

*"Reasoning about Referential Expressions"*

The Iterated Best Response (IBR) model is a
game-theoretic approach to formal pragmatics that spells out pragmatic
reasoning as back- and-forth reasoning about interlocutors’ rational
choices and beliefs (Franke, 2011; Jäger, 2011). Two studies
investigated the production and comprehension of referential expression
within this framework. Manipulating the complexity of inferences
involved in production and comprehension of referential expressions
yielded an intriguing asymmetry: comprehension performance is better
than production in corresponding complex inference tasks, but worse on
simpler ones. This is not predicted by standard formulations of IBR,
which makes categorical predictions about rational choices. However, a
variant of IBR that uses a stochastic instead of a categorical choice
function and assumes that players assume a distribution over
lower-level strategic types (Iterated Quantal Response, IQR) is found
to provide a good fit to the data. The relation of these results to
Frank & Goodman (2011)'s model of pragmatic inference is discussed.

**Michael Franke**—

*"The Use of Quantifiers: Set Size & Typicality"*

Two recent empirical studies have investigated
intuitive typicality/naturalness judgements of the scalar quantifier
/some/ in connection with referent sets of different cardinality (Degen
& Tanenhaus 2011/submitted, van Tiel 2012). In distinction to
previous interpretations of these typicality data, I conjecture that
the mean typicality rating of a quantifier given a set reflects the
degree of likelihood that a speaker would use that quantifier to
describe that set. Support for this conjecture comes from a
quantitative model that seems capable of predicting the data almost
perfectly. Assuming that numerals within the subitizing range, as well
as quantifiers /most/, /many/ and /all/ are available but differently
costly alternatives, we obtain a tight numerical fit from a
noise-affected model of a truth-conforming speaker.

**Noah Goodman**—

*"Uncertainty in Pragmatics and Semantics"*

Viewing language as a form of rational action
suggests applying tools developed for Bayesian models of social
cognition. I follow this idea to build models of language understanding
in simple reference games and scalar implicature. I show that these
models capture the quantitative details of human judgements in several
behavioral experiments. I will then explore the different ways to treat
semantic free variables in a Bayesian setting. By fixing these
variables at the level of pragmatic listener, we can derive the
principle of division of pragmatic labor and explain some puzzling
effects in the semantics of gradeable adjectives.

**Gerhard Jäger**—

*"The Iterated Best Response Model of game theoretic pragmatics and its relatives"*

The talk will give an overview of the Iterated
Best Response model of game theoretic pragmatics. After presenting the
model and going through basic examples, I will discuss scenarios where
the interests of the interlocutors are not aligned, or if they are
boundedly rational. Special attention will be devoted to the "Iterated
Quantal Response" (IQR) variant of the model. This variant is inspired
by recent work in behavioral game theory and makes probabilistic
predictions. Therefore it lends itself readily for modeling
experimental data.