Details
Original language | English |
---|---|
Pages (from-to) | 246-263 |
Number of pages | 18 |
Journal | Biometrical Journal |
Volume | 55 |
Issue number | 2 |
Early online date | 11 Feb 2013 |
Publication status | Published - Mar 2013 |
Abstract
Diversity indices might be used to assess the impact of treatments on the relative abundance patterns in species communities. When several treatments are to be compared, simultaneous confidence intervals for the differences of diversity indices between treatments may be used. The simultaneous confidence interval methods described until now are either constructed or validated under the assumption of the multinomial distribution for the abundance counts. Motivated by four example data sets with background in agricultural and marine ecology, we focus on the situation when available replications show that the count data exhibit extra-multinomial variability. Based on simulated overdispersed count data, we compare previously proposed methods assuming multinomial distribution, a method assuming normal distribution for the replicated observations of the diversity indices and three different bootstrap methods to construct simultaneous confidence intervals for multiple differences of Simpson and Shannon diversity indices. The focus of the simulation study is on comparisons to a control group. The severe failure of asymptotic multinomial methods in overdispersed settings is illustrated. Among the bootstrap methods, the widely known Westfall-Young method performs best for the Simpson index, while for the Shannon index, two methods based on stratified bootstrap and summed count data are preferable. The methods application is illustrated for an example.
Keywords
- Bootstrap, Extra-multinomial variability, Overdispersion, Shannon index, Simpson index, Simultaneous coverage probability
ASJC Scopus subject areas
- Mathematics(all)
- Statistics and Probability
- Decision Sciences(all)
- Statistics, Probability and Uncertainty
Sustainable Development Goals
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In: Biometrical Journal, Vol. 55, No. 2, 03.2013, p. 246-263.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Simultaneous confidence intervals for comparing biodiversity indices estimated from overdispersed count data
AU - Scherer, Ralph
AU - Schaarschmidt, Frank
AU - Prescher, Sabine
AU - Priesnitz, Kai U.
PY - 2013/3
Y1 - 2013/3
N2 - Diversity indices might be used to assess the impact of treatments on the relative abundance patterns in species communities. When several treatments are to be compared, simultaneous confidence intervals for the differences of diversity indices between treatments may be used. The simultaneous confidence interval methods described until now are either constructed or validated under the assumption of the multinomial distribution for the abundance counts. Motivated by four example data sets with background in agricultural and marine ecology, we focus on the situation when available replications show that the count data exhibit extra-multinomial variability. Based on simulated overdispersed count data, we compare previously proposed methods assuming multinomial distribution, a method assuming normal distribution for the replicated observations of the diversity indices and three different bootstrap methods to construct simultaneous confidence intervals for multiple differences of Simpson and Shannon diversity indices. The focus of the simulation study is on comparisons to a control group. The severe failure of asymptotic multinomial methods in overdispersed settings is illustrated. Among the bootstrap methods, the widely known Westfall-Young method performs best for the Simpson index, while for the Shannon index, two methods based on stratified bootstrap and summed count data are preferable. The methods application is illustrated for an example.
AB - Diversity indices might be used to assess the impact of treatments on the relative abundance patterns in species communities. When several treatments are to be compared, simultaneous confidence intervals for the differences of diversity indices between treatments may be used. The simultaneous confidence interval methods described until now are either constructed or validated under the assumption of the multinomial distribution for the abundance counts. Motivated by four example data sets with background in agricultural and marine ecology, we focus on the situation when available replications show that the count data exhibit extra-multinomial variability. Based on simulated overdispersed count data, we compare previously proposed methods assuming multinomial distribution, a method assuming normal distribution for the replicated observations of the diversity indices and three different bootstrap methods to construct simultaneous confidence intervals for multiple differences of Simpson and Shannon diversity indices. The focus of the simulation study is on comparisons to a control group. The severe failure of asymptotic multinomial methods in overdispersed settings is illustrated. Among the bootstrap methods, the widely known Westfall-Young method performs best for the Simpson index, while for the Shannon index, two methods based on stratified bootstrap and summed count data are preferable. The methods application is illustrated for an example.
KW - Bootstrap
KW - Extra-multinomial variability
KW - Overdispersion
KW - Shannon index
KW - Simpson index
KW - Simultaneous coverage probability
UR - http://www.scopus.com/inward/record.url?scp=84874996461&partnerID=8YFLogxK
U2 - 10.1002/bimj.201200157
DO - 10.1002/bimj.201200157
M3 - Article
C2 - 23401312
AN - SCOPUS:84874996461
VL - 55
SP - 246
EP - 263
JO - Biometrical Journal
JF - Biometrical Journal
SN - 0323-3847
IS - 2
ER -