Item


Bayesian-multiplicative treatment of count zeros in compositional data sets

Compositional count data are discrete vectors representing the numbers of outcomes falling into any of several mutually exclusive categories. Compositional techniques based on the log-ratio methodology are appropriate in those cases where the total sum of the vector elements is not of interest. Such compositional count data sets can contain zero values which are often the result of insufficiently large samples. That is, they refer to unobserved positive values that may have been observed with a larger number of trials or with a different sampling design. Because the log-ratio transformations require data with positive values, any statistical analysis of count compositions must be preceded by a proper replacement of the zeros. A Bayesian-multiplicative treatment has been proposed for addressing this count zero problem in several case studies. This treatment involves the Dirichlet prior distribution as the conjugate distribution of the multinomial distribution and a multiplicative modification of the non-zero values. Different parameterizations of the prior distribution provide different zero replacement results, whose coherence with the vector space structure of the simplex is stated. Their performance is evaluated from both the theoretical and the computational point of view

This research was supported by the Ministerio de Economia y Competividad under the project ’METRICS’ Ref. MTM2012-33236, by the Agencia de Gestio d’Ajuts Universitaris i de Recerca of the Generalitat de Catalunya under the project Ref: 2009SGR424, and by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). The authors also gratefully acknowledge the support by the Operational Program Education for Competitiveness-European Social Fund (project CZ.1.07/2.3.00/20.0170 of the Ministry of Education, Youth and Sports of the Czech Republic)

SAGE Publications

Manager: Ministerio de Economía y Competitividad (Espanya)
Generalitat de Catalunya. Agència de Gestió d’Ajuts Universitaris i de Recerca
Author: Martín Fernández, Josep Antoni
Hron, Karel
Templ, Matthias
Filzmoser, Peter
Palarea Albaladejo, Javier
Abstract: Compositional count data are discrete vectors representing the numbers of outcomes falling into any of several mutually exclusive categories. Compositional techniques based on the log-ratio methodology are appropriate in those cases where the total sum of the vector elements is not of interest. Such compositional count data sets can contain zero values which are often the result of insufficiently large samples. That is, they refer to unobserved positive values that may have been observed with a larger number of trials or with a different sampling design. Because the log-ratio transformations require data with positive values, any statistical analysis of count compositions must be preceded by a proper replacement of the zeros. A Bayesian-multiplicative treatment has been proposed for addressing this count zero problem in several case studies. This treatment involves the Dirichlet prior distribution as the conjugate distribution of the multinomial distribution and a multiplicative modification of the non-zero values. Different parameterizations of the prior distribution provide different zero replacement results, whose coherence with the vector space structure of the simplex is stated. Their performance is evaluated from both the theoretical and the computational point of view
This research was supported by the Ministerio de Economia y Competividad under the project ’METRICS’ Ref. MTM2012-33236, by the Agencia de Gestio d’Ajuts Universitaris i de Recerca of the Generalitat de Catalunya under the project Ref: 2009SGR424, and by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). The authors also gratefully acknowledge the support by the Operational Program Education for Competitiveness-European Social Fund (project CZ.1.07/2.3.00/20.0170 of the Ministry of Education, Youth and Sports of the Czech Republic)
Format: application/pdf
Document access: http://hdl.handle.net/10256/10925
Language: eng
Publisher: SAGE Publications
Collection: info:eu-repo/semantics/altIdentifier/doi/10.1177/1471082X14535524
info:eu-repo/semantics/altIdentifier/issn/1471-082X
info:eu-repo/semantics/altIdentifier/eissn/1477-0342
info:eu-repo/grantAgreement/MINECO//MTM2012-33236/ES/METODOS ESTADISTICOS EN ESPACIOS RESTRINGIDOS/
AGAUR/2009-2014/2009 SGR-424
Rights: Tots els drets reservats
Subject: Estadística bayesiana
Bayesian statistical decision theory
Distribució (Teoria de la probabilitat)
Distribution (Probability theory)
Dirichlet, Distribució de
Dirichlet distribution
Title: Bayesian-multiplicative treatment of count zeros in compositional data sets
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

Subjects

Authors