Spradley & Jantz metric method involves which key concept?

• A. Sectioning points (sp) dividing male & female measurements
• B. Principal component analysis of skull metrics
• C. Visual inspection of pelvis
• D. DNA analysis

Answer: (A)

The key idea is using sectioning points, which are fixed dividing values for each skull measurement that separate typical male from typical female values. In the Spradley & Jantz metric method, each dimension has its own threshold derived from a known-sex reference sample. When you measure a skull, you compare the measurement to its sectioning point: if the value falls on the male side, that measurement supports male, and if it falls on the female side, that measurement supports female. By looking at multiple metrics and aggregating those results, you arrive at a sex estimate without relying on multivariate models. This approach is different from using principal components or discriminant analysis, isn’t a subjective visual assessment, and doesn’t involve DNA analysis.