Various nonparametric methods have been introduced to solve real problems. The most appealing aspect for the recursive partitioning user is the final tree that provides a comprehensive description of the phenomenon in different frameworks such as marketing, credit scoring, finance, medical diagnosis, etc. As a matter of fact, users very often accept statistical results only if these confirm theoretical hypotheses on the phenomenon derived from prior knowledge. Thus, several open questions arise when using such heuristic tools; in recursive partitioning the most difficult pertains to which tree to consider for explaining the dependence data structure and how to evaluate the accuracy of the final tree classifier if this should be extended to unseen objects without considering any ¡Èinferential dogma¡É. This latter aspect makes recursive partitioning methods to be considered both as an exploratory tool and as a confirmatory nonparametric model, also known as decision rule. A distinction is made between whether to explore dependency (exploraion) or to predict and decide about future responses on the basis of the selected predictors (confirmation).

We will cover new statistical and computational topics in recursive partitioning emphasizing the use of tree based models for exploratory and confirmative goals, as well as discussing alternatives to standard recursive partitioning algorithms and presenting applications on real complex data.

Focus:

Tree-based methods
Non-standard data
Data editing
Data mining
Interaction effects models
Ensemble classifiers

Co-Chairs:

Roberta Siciliano Dipartimento di Matematica e Statistica University of Naples Federico II Via Cintia, Monte S. Angelo I-80126, Napoli ITALY Tel: +39 081/675120 Fax: +39 081/675109 Email: roberta@unina.it	Jacqueline J. Meulman P.O. Box 9555, Pieter de la Court building 2300 RB Leiden, Wassenaarseweg 52,The Netherlands Tel: +31-71-527 4105 Fax: +31-71-527 3865 Email: meulman@fsw.leidenuniv.nl
Claudio Conversano Department of Economics University of Cassino Via Mazzaroppi, Cassino(FR), ITALY I-03043 Tel: +39 0776 2993448 Fax: +39 0776 310892 Email: c.conversano@unicas.it