Problems of Identification and Quantification in Archaeozoological Analysis, Part II: Presentation of an Alternative Counting Method

Abstract

Archaeozoologists commonly use Number of Identified SPecimens (NISP) and Minimum Number of Elements (MNE) as measures of anatomical abundances. According to a blind test examining the reproducibility and accuracy of identifications of ungulate remains (Morin et al., Part I, Journal of Archaeological Method and Theory, doi: 10.1007/s10816-016-9300-4), NISP provides estimates of skeletal abundances that are less robust than those based on MNE. However, although results were improved with the latter method, MNE is not free of problems. Here, we show through an analysis of paired NISP-MNE data for 24 classes of elements that MNE is prone to inflate the representation of rare parts (as measured by NISP), a phenomenon more strongly expressed in certain elements than in others. Moreover, some elements show a wide scatter of points, which raises issues of data reproducibility. MNE is also known for being seriously affected by aggregation methods. These fundamental problems severely undermine the value of MNE as a measure of abundance. This article introduces an alternative counting method that avoids many of the weaknesses of MNE. This counting method, called the Number of Distinct Elements (NDE), focuses on the occurrence of pre-determined, invariant landmarks counted on mutually exclusive specimens. Preliminary experimental results suggest that NDE counts are robust predictors of skeletal, and perhaps taxonomic, abundances. Moreover, the NDE approach eliminates the complex and time-consuming task of spreading or drawing specimens to identify fragment overlap. Furthermore, NDE values are additive and easy to calculate. Given these features, the NDE approach represents a compelling alternative to MNE in archaeozoological analysis.