Seminari di probabilita' e statistica al Politecnico di Torino

["Federica Giummole'" <giummole@calvino.polito.it>]

SEMINARI DI PROBABILITA' E STATISTICA AL POLITECNICO DI TORINO

Martedi' 28 gennaio 2003
Aula Buzano, Dipartimento di Matematica, Politecnico di Torino


ore 14:30
GUIDO CONSONNI
Universita' di Pavia
"Prior distributions and model comparison: a causal perspective"
(joint work with Alberto Roverato)

Graphical, and in particular Directed Acyclic Graph (DAG), models are by
now well established tools for describing
and manipulating complex multivariate joint distributions. Recently they
have started being used not only to model
the joint probability behaviour of several variables, as they might arise
naturally in the world, but also when some
interventions force one or more of the variables in the system to take on
some externally assigned value or values.
Describing how the remaining variables are affected by such 'settings'
comes close to causal inference, and in this
context the expression 'causal' DAGs, or better still, intervention DAGs
is often used. To achieve this objective,
novel semantics for DAG models need be introduced, leading to the
important distinction between conditioning by
'observation' and by 'intervention'. It is crucial to realise that two
DAGs, equivalent from a probabilistic viewpoint,
are typically quite distinct from a causal one. They thus need to be
treated as separate entities.
Motivated by Bayesian model comparison, we investigate the consequences of
the causal perspective with particular
regard to the choice of prior distributions on the parameters of nested
intervention DAG models.


ore 16:00
HENRY P. WYNN
University of Warwick (UK)
"Causation and dynamics "


Tutti gli interessati sono invitati a partecipare.

Il programma generale dei seminari di probabilita' e statistica al
Politecnico di Torino e' disponibile
(in versione provvisoria) all'indirizzo
http://calvino.polito.it/~probstat/seminars.html

Cordiali saluti,

		Federica Giummole'


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Federica Giummole'
Dipartimento di Matematica     Tel: +39 011 564 7550
Politecnico di Torino          Fax: +39 011 564 7599
Corso Duca degli Abruzzi 24    email: giummole@calvino.polito.it
10129 Torino                   www: http://calvino.polito.it/~giummole/
ITALY
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