Can whole-drawer images measure up? A reply to Johnson et al. (2013)?

By

Trueman, John W. H.
Yeates, David K.

Type

Article

Date of Publication

2015

Original Publication

ZooKeys

Volume

500

Pages

141-149

Subjects

Digitization , Dragonflies , entomological collections , morphometrics , Museum Collections , Odonata

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.500.9139

 

Abstract

Johnson et al. (2013) found that morphometric measurements of dragonfly wings taken from actual specimens and measurements taken from whole-drawer images of those specimens were equally accurate. We do not believe that their conclusions are justified by their data and analysis. Our reasons are, first, that their study was constrained in ways that restrict the generalisability of their results, but second, and of far greater significance, their statistical approach was entirely unsuited to their data and their results misled them to erroneous conclusions. We offer an alternative analysis of their data as published. Our reanalysis demonstrates, contra Johnson et al., that measurements from scanned images are not a reliable substitute for direct measurement.