Common statistical errors in morphometry.

Morphometry is the quantitative measurement of morphological features. Data is usually obtained by probabilistic sampling techniques and is often markedly variable due to intrinsic variations in sampled specimens. Statistical analyses are required both to allow for and to control such variability. Care is needed in the analysis of morphometric data if false conclusions are to be avoided. Examination of any reasonably sized sample of publications in morphometry usually results in the detection of at least several common errors of statistical practice. Commonest errors involve statistics being carried out on untransformed percentage data, statistics on ratios, repeated multiple applications of tests designed for single comparisons, misuse of correlation and violations of statistical assumptions.