Use and Multifactorial Reconciliation of Uniface Reduction Measures: A Pilot Study at the Nobles Pond Paleoindian Site

Abstract

How much stone tools are reduced and their form changed from first use to discard bears upon issues such as typological integrity, curation rate, and effects of occupation span. But degree of reduction depends partly upon the measures used to gauge it. Most studies involve single indices that gauge reduction in different ways or at different scales, so results are difficult to compare between studies. In this pilot study, we compare four allometric reduction measures—one each based on length, length:thickness ratio, volume, and mass, estimated by comparing observed values in discarded tools to estimated original values—for consistency when applied to an endscraper sample from the Nobles Pond Paleoindian site in Ohio, USA. Fitted to the Weibull distribution, all measures suggest attrition compared to experimental controls, but variation among them demands reconciliation. A multifactorial method that weights individual measures by their principal-component loadings suggests attritional discard at increasing rate as reduction advances. More importantly, it addresses the growing problem of reconciling the many reduction measures in use, a major concern in this expanding research area.

Quantifying knapping actions: a method for measuring the angle of blow on flakes

“…The EPA-PD model often performs less well when applied to less controlled experimental replication assemblages and archeological assemblages. Although several studies have attempted to improve the EPA-PD model by adding other attributes such as platform width, platform area, and platform shape (Dibble 1997;Davis and Shea 1998;Shott et al 2000;Clarkson and Hiscock 2011;Lin et al 2013;Dogandžić et al 2015;Shott and Seeman 2017;Režek et al 2018;McPherron et al 2020), the ability of the model and its variants to accurately predict the original flake size is still limited. In their paper on the topic, Dibble and Rezek (2009) found that exterior platform angle, platform depth, and angle of blow all influenced flake mass, yet the angle of blow was mostly dropped from subsequent presentations of the model because the parameter could not be measured on the flakes themselves (see also Shott and Seeman 2017).…”

Parts and Wholes: Reduction Allometry and Modularity in Experimental Folsom Points

“…There are numerous geometric measures for unifacial tools (e.g., Shott and Seeman 2017:729–731). For points, Hoffman proposed an allometric measure: a ratio of point length to blade edge-angle that captures “a dimension or scale of variability that can be used .…”

“…Moreover, different ranges of the Weibull shape parameter β implicate different failure scenarios. When 1 < β < 2, failure rate increases at a decreasing rate consistent with early wear-out failure, when β = 2 failure increases at a constant rate, and when β >2 failure increases at increasing rate (e.g., Douglass et al 2018; Morales 2016; Shott and Seeman 2017:732). Similarly, reduction distributions can distinguish between, for instance, competing scenarios of Folsom hunting practices by linking the duration of point use—and, by extension, distributions themselves—to different assumptions about group size and hunting rates (Hunzicker 2005:55–60).…”

“…In the process, the argument both invokes the utility concept (Shott 1996) and makes the form of point types’ reduction distributions (Miller 2018:Figure 3.1) relevant to sophisticated behavioral modeling. The use of multiple reduction measures and their multifactorial reconciliation establish comparability between measures and studies (Shott and Seeman 2017), quantifying the degree of curation and grounding behavioral models in data.…”

Inferring Use-Life Mean and Distribution: A Pottery Ethnoarchaeological Case Study from Michoacán

“…Human death-age distributions must be inferred from age-related osteological changes. Stone tool use-life distributions can be inferred from degree or pattern of reduction (Douglass et al 2018; Morales 2016; Shott and Seeman 2017). Until the relationship between vessel age and wear develops beyond its promising start (Skibo 1992), ceramic use-life distributions remain elusive except in ethnoarchaeological context.…”