Ecological Research

, Volume 19, Issue 2, pp 165–167 | Cite as

Angular transformation – another effect of different sample sizes

Original Articles

Angular transformation has been widely used to analyze proportions or percentages in ecology. A new type of artifact can arise by applying angular transformation to proportions or percentages. Proportions with the same mean or expected value, but with different sample sizes (denominator of proportions), have different means or expected values after this transformation. Overdispersion causes a larger deviation of the expected value after the transformation. Angular transformation should be avoided unless the sample size (denominator of proportions) is the same for all the proportions analyzed.

Key words

angular transformation bias sample size statistical analyses transformation 

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Copyright information

© Blackwell Publishing Ltd 2004

Authors and Affiliations

  1. 1.Department of BiologyKyushu UniversityFukuokaJapan

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