Accuracy of the Transition Analysis 3 (TA3) Method for Age Estimation in the John A. Williams Human Skeletal Collection

Item

Title
Accuracy of the Transition Analysis 3 (TA3) Method for Age Estimation in the John A. Williams Human Skeletal Collection
Creator
Blue I. Wonhof
Degree Name
Master of Science in Justice Studies
Project Type
Thesis
Date
6/15/2025
Abstract
This study evaluates the accuracy and reliability of Transition Analysis 3 (TA3), a multifactorial forensic age estimation method, using 71 individuals from the John A. Williams Human Skeletal Collection at Western Carolina University. Individuals were selected based on known age-at-death and sufficient skeletal preservation to be scored for over 75% of the 121 morphological traits specified by TA3. Age estimations were generated using standardized procedures and analyzed in IBM SPSS to assess absolute error, intraobserver reliability, and the role of demographic and skeletal variables in estimation accuracy. Results revealed a mean absolute error (MAE) of 8.14 years, with 92.96% of individuals falling within the TA3-predicted age intervals. While intraobserver agreement was low overall (Cohen’s Kappa = 0.079), perfect agreement (Kappa = 1.0) was achieved when individuals were grouped by age category (young, middle, and old adult). No significant differences in error were observed by sex; however, younger individuals exhibited higher error rates (p = .002). Skeletal element-specific analyses revealed variation in reliability, with the trapezium yielding the lowest average error (5.93) and the scapula the highest (9.74). By region, the tibia, fibula, and calcaneus yielded the lowest MAE (7.34) and the humerus the highest (9.2). These findings bring to light both the limitations of TA3 in forensic age estimation, particularly in younger age groups, and the potential of certain skeletal regions.
Keywords
forensic antropology
age estimation
Transition Analysis
Committee Member
Misty Weitzel
Jonathan Bethard
Jerielle Cartales
Rights
Western Oregon University Library has determined, as of 06/20/2025, this item is in copyright, which is held by the author. Users may use the item in accordance with copyright limitations and exceptions, including fair use. For other uses, please ask permission from the author.
https://rightsstatements.org/page/InC/1.0/?language=en
Language
eng
Type
Text
Identifier
BlueWonhof_Thesis_2025
Item sets
Graduate Work
Media
BlueWonhof_Thesis_2025.pdf