Comparing Traditional Age Estimation at the Defense POW/MIA Accounting Agency to Age Estimation Using Random Forest Regression

Abstract

Age estimation from developmental traits is typically assessed in isolation, where an age range is derived from known individuals that exhibit that degree of fusion. There are no objective means for incorporating developmental evidence from multiple areas of the skeleton into one cohesive age estimate. This limitation is obvious in the casework at the Defense POW/MIA Accounting Agency (DPAA), where subjectivity is introduced into age estimates based on multiple age indictors. This holds true even when age is derived from one source, The 1957 study by McKern and Stewart). This study uses 388 individuals from the McKern and Stewart study and 41 individuals from the Battle of Tarawa and uses Random Forest Regression (RFR) to estimate an age interval using multiple age indicators. These RFR estimates are compared to age estimates from the Forensic Anthropology Reports (FARs). Overall, FAR age estimates are more accurate (92.7%) than those from the two RFR models (80.5% and 76.6%). This increase in accuracy comes at the cost of some precision (FARs average age interval of 8.1 years and RFR average age intervals of 6.3 and 6.4 years). The RFR models prefer age indicators with late fusion, such as the medial clavicle, and the pubic symphysis, which exhibit a combination of developmental and degenerative ages in morphology. Some avenues for further research are discussed.