Accuracy and power in fluctuating asymmetry studies: effects of sample size and number of within-subject repeats

This paper presents results from simulations investigating the effect of sa mple size, number of within-subject repeats and relative degree of measurem ent error on the power and accuracy of test for fluctuating asymmetry (FA). These data confirm that sampling variation of population-level FA-estimate s is large and that high sample size is required to obtain reasonably high power when testing for FA or comparing FA levels between populations. The r esults also clearly show that increasing the number of within-subject repea ts can dramatically increase accuracy and power when measurement error is r elatively high.