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How long is a piece of Strix? Methods in measuring and measuring the measurers

Abstract

An experiment to quantify intra- and interobserver error in anatomical measurements found that interobserver measurements can vary by over 14% of mean specimen length; disparity in measurement increases logarithmically with the number of contributors; instructions did not reduce variation or measurement disparity; scale of the specimen influenced the precision of measurement (relative error increasing with specimen size); different methods of taking a measurement yielded different results, although they did not differ in terms of precision, and topographical complexity of the elements being considered may potentially influence error (error increasing with complexity). These results highlight concerns about introduction of noise and potential bias that should be taken into account when compiling composite datasets and meta-analyses.

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Acknowledgments

We gratefully acknowledge the unidentified reviewer whose comments have substantially improved the structure and content of this paper. We especially thank Dr. Gareth Dyke and the others involved in the conference organisation of the 56th Symposium of Vertebrate Palaeontology and Comparative Anatomy (Dublin, 2008) for facilitating the experiment. We are grateful to all of the SVPCA attendees for constructive discussion and the 51 individual delegates who contributed their measurements. Additional thanks goes to Beulah Garner for her comments on this manuscript.

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Correspondence to Paolo Viscardi.

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Communicated by T. Bartolomaeus.

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Viscardi, P., Sakamoto, M. & Sigwart, J.D. How long is a piece of Strix? Methods in measuring and measuring the measurers. Zoomorphology 129, 185–194 (2010). https://doi.org/10.1007/s00435-010-0111-y

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Keywords

  • Measurement
  • Methods
  • Composite data
  • Morphometrics
  • Error
  • Meta-analysis
  • Anatomy
  • Observer error