The application of decision trees for estimating osteological sex from common measurements of the skull.

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Bibliographic Details
Title: The application of decision trees for estimating osteological sex from common measurements of the skull.
Authors: Ferrell MJ; Department of Anthropology, University of Kentucky, Lexington, Kentucky, USA., Schultz JJ; Department of Anthropology, University of Kentucky, Lexington, Kentucky, USA., Adams DM; Department of Anthropology, University of Central Florida, Orlando, Florida, USA.; National Center for Forensic Science, Orlando, Florida, USA.
Source: Journal of forensic sciences [J Forensic Sci] 2025 May; Vol. 70 (3), pp. 854-867. Date of Electronic Publication: 2025 Mar 26.
Publication Type: Journal Article
Language: English
Journal Info: Publisher: Blackwell Pub Country of Publication: United States NLM ID: 0375370 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1556-4029 (Electronic) Linking ISSN: 00221198 NLM ISO Abbreviation: J Forensic Sci Subsets: MEDLINE
Imprint Name(s): Publication: 2006- : Malden, MA : Blackwell Pub.
Original Publication: [Chicago, Ill.] : Callaghan and Co., 1956-
MeSH Terms: Decision Trees* , Sex Determination by Skeleton*/methods , Skull*/anatomy & histology, Adolescent ; Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; Black or African American ; Cephalometry ; Forensic Anthropology ; White
Abstract: Skull measurements are commonly evaluated for osteological sex estimation in forensic anthropology, and decision tree-based classification models for the skull may improve accuracy compared to current metric methods. Additionally, decision trees can provide accurate sex classification with a limited number of measurements, which is valuable when analyzing fragmentary remains. Thus, the present study seeks to test the utility of decision trees for generating sex classification models from metric variables of the skull. Twenty-one skull measurements were evaluated for 403 adult males and females. Relative technical error of measurement was used to assess intraobserver error, and two-way ANOVAs and aligned rank transformation were used to examine the effects of sex, population, age, and temporal period on the measurements. The data set was split into 80% training and 20% holdout testing samples to assess the predictive accuracy of each tree. Trees were generated for the skull and cranium, with models for European Americans, African Americans, and the pooled population sample. Overall, the recommended trees for the cranium achieved higher accuracies (85.3-95.0%) compared to the skull trees (84.0-92.5%). Accuracies for the population-inclusive trees ranged from 84.0% to 85.3%, whereas the European American (92.5-95.0%) and African American (90.9%) trees achieved slightly higher accuracies. Improved accuracies were achieved compared to previous decision tree research as well as compared to current metric methods for the skull. These trees provide an additional option for estimating osteological sex, particularly when morphological methods do not yield adequate classification accuracies or cannot be assessed due to damage.
(© 2025 American Academy of Forensic Sciences.)
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Contributed Indexing: Keywords: biological profile; decision trees; forensic anthropology; machine learning; sex estimation; skull
Entry Date(s): Date Created: 20250326 Date Completed: 20250502 Latest Revision: 20250514
Update Code: 20250514
DOI: 10.1111/1556-4029.70031
PMID: 40135464
Database: MEDLINE
Description
Abstract:Skull measurements are commonly evaluated for osteological sex estimation in forensic anthropology, and decision tree-based classification models for the skull may improve accuracy compared to current metric methods. Additionally, decision trees can provide accurate sex classification with a limited number of measurements, which is valuable when analyzing fragmentary remains. Thus, the present study seeks to test the utility of decision trees for generating sex classification models from metric variables of the skull. Twenty-one skull measurements were evaluated for 403 adult males and females. Relative technical error of measurement was used to assess intraobserver error, and two-way ANOVAs and aligned rank transformation were used to examine the effects of sex, population, age, and temporal period on the measurements. The data set was split into 80% training and 20% holdout testing samples to assess the predictive accuracy of each tree. Trees were generated for the skull and cranium, with models for European Americans, African Americans, and the pooled population sample. Overall, the recommended trees for the cranium achieved higher accuracies (85.3-95.0%) compared to the skull trees (84.0-92.5%). Accuracies for the population-inclusive trees ranged from 84.0% to 85.3%, whereas the European American (92.5-95.0%) and African American (90.9%) trees achieved slightly higher accuracies. Improved accuracies were achieved compared to previous decision tree research as well as compared to current metric methods for the skull. These trees provide an additional option for estimating osteological sex, particularly when morphological methods do not yield adequate classification accuracies or cannot be assessed due to damage.<br /> (© 2025 American Academy of Forensic Sciences.)
ISSN:1556-4029
DOI:10.1111/1556-4029.70031