**recommended application of these traits is in MorphoPASSE- www.MorphoPASSE.com (Klales 2018)
rather than the older Klales et al. (2012) method below**
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A Revised Method of Sexing the Human Innominate Using
Phenice’s Nonmetric Traits and Statistical Methods
Supplemental material to Klales et al. (2012)
This website has been created to provide supplemental photographs for scoring the revised Phenice (1969) traits proposed by Klales et al. (2012) found in the American Journal of Physical Anthropology 149:104-114.
Above you will find a tab for each of the three traits (VA = ventral arc, SPC = subpubic contour, MA = medial aspect of the ischio-pubic ramus). On each page the schematic drawings for trait scoring and a photograph of real bone for each score is presented. Additionally, information on how to properly orient the bone for scoring is included.
Sex Classification Based on Scores:
The logistic regression equation to apply to all three trait scores is:
2.726 (VA) + 1.214 (MA) + 1.073 (SPC) - 16.312
The probability of being female based on the score can be calculated by the equation pf = 1/(1 + escore) and the probability for males, pm = 1 – pf (Press and Wilson, 1978). An unknown individual is classified into the sex with the greater probability; an individual is classified as a female if the score is less than zero.
Download spreedsheet HERE to easily calculate Male/Female probability
AJPA Article Abstract:
The traits of the pubis described by Phenice (1969) have been used extensively by physical anthropologist for sex estimation. This study investigates all three of Phenice's characteristics in an approach similar to Walker’s (2008) study using observations from the cranium and mandible. The ventral arc, the subpubic contour, and the medial aspect of the ischio-pubic ramus were scored on a five-point ordinal scale from a sample of 310 adult, left innominates of known ancestry and sex from the Hamann-Todd Human Osteological Collection and the W.M. Bass Donated Skeletal Collection. Four observers with varying levels of experience blindly scored each trait using new descriptions and illustrations adapted from those originally created by Phenice. The scores were then analyzed with ordinal logistic regression. Using all three traits for sex classification, the mean correct classification rate was 94.5% cross-validated for experienced observers. Intra- and interobserver error in trait scoring was low for all three traits and agreement levels ranged from moderate to substantial. Tests of the method on an independent validation sample provided a classification accuracy of 86.2%. This revision of the Phenice (1969) technique is a reliable and valid method of sex estimation from the human innominate that meets the Daubert criteria for court admissibility.
Photo Acknowledgements:
Thanks go to Lyman Jellema and Laura Diefenbach for photographing some of the innominates. Innominate photos are courtesy of Dr. Dennis Dirkmaat of Mercyhurst University, Dr. Todd Fenton of Michigan State University, Dr. Robert Hoppa of the University of Manitoba, and the Cleveland Museum of Natural History.
Copyrighted to Alexandra Klales 2012
Last updated 01 January 2017
Above you will find a tab for each of the three traits (VA = ventral arc, SPC = subpubic contour, MA = medial aspect of the ischio-pubic ramus). On each page the schematic drawings for trait scoring and a photograph of real bone for each score is presented. Additionally, information on how to properly orient the bone for scoring is included.
Sex Classification Based on Scores:
The logistic regression equation to apply to all three trait scores is:
2.726 (VA) + 1.214 (MA) + 1.073 (SPC) - 16.312
The probability of being female based on the score can be calculated by the equation pf = 1/(1 + escore) and the probability for males, pm = 1 – pf (Press and Wilson, 1978). An unknown individual is classified into the sex with the greater probability; an individual is classified as a female if the score is less than zero.
Download spreedsheet HERE to easily calculate Male/Female probability
AJPA Article Abstract:
The traits of the pubis described by Phenice (1969) have been used extensively by physical anthropologist for sex estimation. This study investigates all three of Phenice's characteristics in an approach similar to Walker’s (2008) study using observations from the cranium and mandible. The ventral arc, the subpubic contour, and the medial aspect of the ischio-pubic ramus were scored on a five-point ordinal scale from a sample of 310 adult, left innominates of known ancestry and sex from the Hamann-Todd Human Osteological Collection and the W.M. Bass Donated Skeletal Collection. Four observers with varying levels of experience blindly scored each trait using new descriptions and illustrations adapted from those originally created by Phenice. The scores were then analyzed with ordinal logistic regression. Using all three traits for sex classification, the mean correct classification rate was 94.5% cross-validated for experienced observers. Intra- and interobserver error in trait scoring was low for all three traits and agreement levels ranged from moderate to substantial. Tests of the method on an independent validation sample provided a classification accuracy of 86.2%. This revision of the Phenice (1969) technique is a reliable and valid method of sex estimation from the human innominate that meets the Daubert criteria for court admissibility.
Photo Acknowledgements:
Thanks go to Lyman Jellema and Laura Diefenbach for photographing some of the innominates. Innominate photos are courtesy of Dr. Dennis Dirkmaat of Mercyhurst University, Dr. Todd Fenton of Michigan State University, Dr. Robert Hoppa of the University of Manitoba, and the Cleveland Museum of Natural History.
Copyrighted to Alexandra Klales 2012
Last updated 01 January 2017
