Re: [ABE-L]: Seminario Thomas Louis, dia 18/07 as 16h (fwd)

["Clarice G.B. Demetrio" <clarice@carpa.ciagri.usp.br>]

Seminario
>
> Data: 18/07/07 as 16h
>
> Abstract:
> PERFORMANCE OF OPTIMAL BAYESIAN RANKING METHODS
> Thomas A. Louis, PhD
> Department of Biostatistics
> Johns Hopkins Bloomberg School of Public Health
>
> Health services evaluations, environmental assessments, school
> e©ectiveness studies and
> identiîcation of active genes depend on the relative position (ranks) of
> unit-speciîc values.
> Therefore, ranking to identify high or low rank units (producing league
> tables) is an im-
> portant goal. Invalid ranks or inappropriate interpretation can have
> serious science, policy
> and înancial consequences. When uncertainties vary over units to be
> ranked, guidance is
> needed. For example, basing ranks on hypothesis tests to identify
> relatively poor perfor-
> mance unfairly penalizes units with relatively low variance because the
> tests have higher
> power; ranking the MLEs unfairly penalizes units with relatively high
> variance because they
> tend to be at the extremes. Valid ranking depends on properly melding the
> order produced by
> point estimates (MLEs) and the uncertainty of these estimates. Bayesian
> modeling coupled
> with loss functions provides the necessary structure.
> We compare MLE-based ranks, those based on the posterior mean of target
> parameters and
> those based on several ranking-relevant loss functions. We evaluate
> performance, showing
> that in most realistic situations even optimal methods have limited
> e©ectiveness and present
> an application to ranking dialysis providers based on standardized
> mortality ratios.
>
>
>   Clarice
> ---------------------------------------------------------------------
> Clarice Garcia Borges Demetrio
> Departamento de Ciencias Exatas      | Phone: +55 019 34294144 R:216
> ESALQ/USP                            | Fax:   +55 019 34294346
> Caixa Postal 9                       | http://ce.esalq.usp.br/
> 13418-900 PIRACICABA, SP             |
> BRASIL                               | clarice@carpa.ciagri.usp.br
>
> --------------------------------------------------------------------
> 52¦ ReuniÆo Anual da RegiÆo Brasileira da Sociedade Internacional de
> Biometria e 12§ Simposio de Estatistica Aplicada a Experimentacao
> Agronomica (SEAGRO)
> 23 a 27/07/2007, Santa Maria, RS
> ---------------------------------------------------------------------
>
>
>> > > > Professor Thomas A. Louis, PhD
>> > > > President of the International Biometric Society
>> > > > Department of Biostatistics
>> > > > Johns Hopkins Bloomberg School of Public Health
>> > > > 615 North Wolfe Street, E3545; Baltimore, MD 21205-2179 USA
>> > > > 410-614-7838(office); 410-955-0958(fax);  202-494-9331(mobile)
>> > > > tlouis@jhsph.edu <mailto:tlouis@jhsph.edu> ;
>> http://www.biostat.jhsph.edu/~tlouis/
>> > > >
>> > > > "Biometry, the active pursuit of biological knowledge by
>> quantitative methods"
>> > > > R. A. Fisher, 1948