Brief communication: The relation between standard error of the estimate and sample size of histomorphometric aging methods
Article first published online: 17 MAY 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 145, Issue 4, pages 658–664, August 2011
How to Cite
Hennig, C. and Cooper, D. (2011), Brief communication: The relation between standard error of the estimate and sample size of histomorphometric aging methods. Am. J. Phys. Anthropol., 145: 658–664. doi: 10.1002/ajpa.21540
- Issue published online: 8 JUL 2011
- Article first published online: 17 MAY 2011
- Manuscript Accepted: 24 MAR 2011
- Manuscript Received: 14 OCT 2010
- Natural Sciences and Engineering Research Council of Canada Discovery. Grant Number: 353618
- sample size;
- forensic anthropology
Histomorphometric aging methods report varying degrees of precision, measured through Standard Error of the Estimate (SEE). These techniques have been developed from variable samples sizes (n) and the impact of n on reported aging precision has not been rigorously examined in the anthropological literature. This brief communication explores the relation between n and SEE through a review of the literature (abstracts, articles, book chapters, theses, and dissertations), predictions based upon sampling theory and a simulation. Published SEE values for age prediction, derived from 40 studies, range from 1.51 to 16.48 years (mean 8.63; sd: 3.81 years). In general, these values are widely distributed for smaller samples and the distribution narrows as n increases—a pattern expected from sampling theory. For the two studies that have samples in excess of 200 individuals, the SEE values are very similar (10.08 and 11.10 years) with a mean of 10.59 years. Assuming this mean value is a ‘true’ characterization of the error at the population level, the 95% confidence intervals for SEE values from samples of 10, 50, and 150 individuals are on the order of ±4.2, 1.7, and 1.0 years, respectively. While numerous sources of variation potentially affect the precision of different methods, the impact of sample size cannot be overlooked. The uncertainty associated with SEE values derived from smaller samples complicates the comparison of approaches based upon different methodology and/or skeletal elements. Meaningful comparisons require larger samples than have frequently been used and should ideally be based upon standardized samples. Am J Phys Anthropol, 2011. © 2011 Wiley-Liss, Inc.