[Statlist] Talk on Statistics 28. 05.2009

[Cecilia Rey]

ETH and University of Zurich

Proff. A.D. Barbour - P. Buehlmann -  L. Held -
H.R. Kuensch - M. Maathuis - W. Stahel - S. van de Geer


***********************************************************           We 
are glad to announce the following talk
       /*Thursday, May 28, 2009, 15.45 HG G 19.1*/

***********************************************************
   /by Alan H. Welsh, The Australian National University, Center for 
Mathematics and its Applications, Canberra/

Titel:
Recent reflections on Extra Zeros in Count Data

////
Abstract:
The simplest way to model count data with extra zeros seems to be to 
include an extra spike at the origin, forming effectively a mixture 
distribution with a degenerate component.  Nonetheless, there are at 
least two different ways of forming the mixture.  It seems not to be 
widely appreciated that, at least when covariates are included, two 
different models result.  In this talk we will describe the two models, 
make a detailed comparison of them and discuss the implications for data 
analysis.  We will illustrate the key points in a re-analysis of data on 
Leadbeater's Possum.

The abstract is also to be found under the following link:  
http://stat.ethz.ch/talks/research_seminar

-- 
ETH Zürich
Seminar für Statistik
Cecilia Rey-Lutz, HG G10.3
Rämistrasse 101                    
CH-8092 Zurich		                      	
mail: rey at stat.math.ethz.ch    	  		
phone: +41 44 632 3438/fax: +41 44 632 1228