Statistical Modelling of Artefact Compositional Data

Abstract

Model‐based methods for clustering artefacts, given their chemical composition, often assume sampling from a mixture of multivariate normal distributions and/or make explicit assumptions about the way in which a composition is formed. It is argued that, analysed within a modelling framework, several important and apparently competing methodologies are more similar than would initially appear. The opportunity is taken to note that models for populations are often not compatible with models for compositions, and that dilution correction—which can be accomplished in a variety of ways—can be interpreted as an attempt to resolve this problem.

Lead isotopic analysis within a multiproxy approach to trace pottery sources. The example of White Slip II sherds from Late Bronze Age sites in Cyprus and Syria

“…A preliminary comparison produced almost identical results using the standardized and logged data, in agreement with what was found by Baxter (1995), which may be due to the elimination of the gross outliers (Baxter, 2001). Here, only the results obtained in the standardized data matrix are presented.…”

Computationally intensive multivariate statistics and relative frequency distributions in archaeology (with an application to the Early Epipaleolithic of the Levant)

“…A formal measure of the between-group dissimilarity e that is, the overall 'goodness of grouping' e can be described as an optimality criterion (OC). There is a wide variety of ways to define the OC, and different optimality criteria can have substantial effects on the cluster analysis results [14,56]. Commonly employed OCs in non-hierarchical cluster analysis (e.g.…”

“…In presenting a case study, we apply the computationally intensive techniques to the statistical analysis of microlithic typological variability among Early Epipaleolithic (ca. 23e18 ka, calibrated 14 C years) assemblages from the Southern Levant.…”

Reconstructing Regional Trajectories: the Provenance and Distribution of Archaic to Hellenistic Ceramics in CentralPisidia(South-west Turkey)

“…The contribution of specific elements to group separation can be observed together with the degree of variability. PCA is commonly used both as a tool to discover subgroups, and to assess the coherence of hypothetical groups suggested by other criteria; for example, petrographic groups, archaeological context and stylistic features (Baxter 2001;Michelaki and Hancock 2011).…”