STATISTICAL-ANALYSIS OF COMPOSITIONAL DATA IN ANATOMY

Background: Variables which describe the composition, or relative size of components, of an organism need to be analysed in an appropriate m anner. Methods: A few of the appropriate descriptive and inferential t echniques have been described and applied to a number of anatomical da ta sets. Results: When applied to data on the composition of the vastu s medialis in adults, a small but significant difference in average mu scle fibre type distribution was demonstrated between males and female s. There was little evidence for a relationship between fibre type dis tribution and age over the range considered. Conclusions: Graphical di splays via ternary diagrams are a simple way of illustrating compositi onal data simultaneously between and within groups. Numerical analysis is likely to involve transformation of original variables before stan dard univariate or multivariate statistical techniques can be used. (C ) 1994 Wiley-Liss, Inc.