Learning from blind tests: Determining the function of experimental grinding stones through use-wear and residue analysis Elspeth H. Hayes a, ⁎, Dries Cnuts b , Christian Lepers b , Veerle Rots b a Centre for Archaeological Science, School of Earth and Environmental Science, University of Wollongong, Northfields Avenue, Wollongong 2522, Australia b Service de Préhistoire, University of Liège, Place du 20-Août 7, 4000 Liège, Belgium abstract article info Article history: Received 22 September 2016 Accepted 1 December 2016 Available online xxxx Blind tests provide an objective means to evaluate the accuracy of functional interpretations based on the pres- ence of use-wear and residue traces on stone tools. Previous blind tests have highlighted interpretive errors com- monly associated with use-wear and residue analyses leading to significant methodological developments in each of the respective fields. While a number of blind tests have been performed on flaked stone tools, only a sin- gle blind test has been published for use-wear on grinding tools. We present the results of a two-part blind test performed on 15 experimental grinding implements that were used in a controlled setting, designed to evaluate the relative importance of residue analysis for determining the worked material (1) when contextual information is available and (2) when contextual information is absent. We argue that use-wear and residue analyses are suc- cessful procedures to identify the use of grinding stones, and that residue analysis may be a particularly valuable means for determining the worked material on tools that have insufficient use-wear development. We suggest that residues should be sufficiently abundant to infer use, if we are to avoid the potential confusion caused by contamination. © 2016 Elsevier Ltd. All rights reserved. Keywords: Functional analysis Stone tools Histological staining Contamination Grinding stones Controlled experiments 1. Introduction Reconstructions of past tool use are possible through the microscop- ic technique of use-wear analysis, where tool use may be inferred by the nature and distribution of specific wear traces on tool surfaces. The characterisation of adhering residues by their visual appearance—both macro and microscopically—and their distribution on the tool surface, can also provide evidence for worked materials. Whilst reconstructions of past tool use have focussed on the examination of flaked stone tools, traces, including use-wear residues (notably starch grains), on grinding stones, have provided evidence for past activities such as food prepara- tion, plant domestication, tool maintenance and craft production (e.g. Adams, 1988, 1999; Attenbrow et al., 1998; Dubreuil, 2004; Dubreuil and Grosman, 2009; Fullagar and Field, 1997; Fullagar et al., 2006, 2008, 2015, 2016; Hamon, 2008, Hayes, 2015; Hayes et al., 2016; Liu et al., 2010a, 2010b, 2011, 2013; Piperno et al., 2004; Revedin et al., 2010; Van Peer et al., 2003; Wright, 1994). In this paper, we explore the value of wear and residue traces on grinding tools for determining the worked material in a multi-staged blind test, with particular focus on the characterisation of residues. Both parts of the test were carried out on the same set of experimental tools (n = 15) used in a controlled setting to process a variety of plant, animal and inorganic materials. Part 1 of the blind test was designed to evaluate the relative importance and reliability of approaches for wear and residue analyses in a context where the grinding stones and sample locations are available, to determine whether the worked material may be identified. Part 2 was designed to evaluate the relative importance of wear and residues documented under high magnification, from samples of these traces without access to the grinding stones or other supporting contextual information. 2. Background 2.1. Blind tests Blind tests have made significant contributions to the methodologi- cal developments of use-wear and residue analyses, providing a means for determining the most reliable way traces of use may be identified and interpreted on stone tools. The earliest blind tests were carried out in the 1970s and 80s on flaked stone tools to evaluate the reliability of use-wear interpretations using low magnification (e.g. Odell and Odell-Vereecken, 1980; Shea, 1987, 1988) and high magnification mi- croscopy (e.g. Bamforth et al., 1990; Keeley and Newcomer, 1977; Knutsson and Hope, 1984; Newcomer et al., 1986). More recently, blind tests have included use-wear observations at both low and high magnifications (e.g. Rots et al., 2006) and analyses of adhering residues Journal of Archaeological Science: Reports 11 (2017) 245–260 ⁎ Corresponding author. E-mail addresses: ehayes@uow.edu.au (E.H. Hayes), dries.cnuts@ulg.ac.be (D. Cnuts), veerle.rots@ulg.ac.be (V. Rots). http://dx.doi.org/10.1016/j.jasrep.2016.12.001 2352-409X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep