title: Can whole-drawer images measure up? A reply to Johnson et al. (2013)?
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.
authors.affiliation: Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
authors.forename: John W H
authors.initials: JW
authors.lastname: Trueman
authors.affiliation: The Australian National Insect Collection, CSIRO National Research Collections Australia, PO Box 1700 Canberra ACT 2601.
authors.forename: David K
authors.initials: DK
authors.lastname: Yeates
keywords: Digitization; Odonata; dragonflies; entomological collections; morphometrics; museum collections