Old stones & new technologies (2011)

Digital imaging techniques are increasingly being seen as an effective means of disseminating information to a world-wide audience and new technologies are beginning to be applied to the oldest of archaeological artefacts; lithic artefacts. A recent Nature paper presenting new evidence for the presence of hominins in northern Europe >0.78 Myr ago used supplementary material in the form of animated micro-CT volume renderings of lithic artefacts to support claims that they were humanly modified [1] . Further work on digital preservation and dissemination of ancient lithic technology led to the suggestion that virtual artefacts created using micro-CT might be “more useful to researchers than 2D drawings and photographs” [2] . The study by Abel and colleagues was designed to assess (a) whether micro-CT could capture the fine surface topology created during production of lithic artefacts and (b) if the technology could visualise missing parts of the production sequence. The results demonstrated the effectiveness of the technology for visualising artefacts and aiding analysis and interpretation. However, the study was limited to artefacts with very clear features that required little interpretation. Unfortunately, the Palaeolithic record is dominated by lithic artefacts that do not fall into this category and traditional visualisation techniques provide an interpreted view of the artefact. Traditional lithic illustration involves collaboration between an illustrator and a lithic specialist. The resulting drawings convey information about the artefact using accepted conventions, signs and marks. The specialist and illustrator decide which details of the artefact they wish to emphasise and whilst good illustrations are accurate they do not necessarily portray every detail of the artefact. Traditional illustrations are thus inescapably subjective and this stands in direct contrast to digital imaging techniques such as micro-CT. This contrast raises questions about the requirements that must be taken into consideration when commissioning visualisations of lithic artefacts. In this paper we explore the requirements of lithic specialists who commission visualisations of lithic artefacts. Considerations include: Production of a permanent record Visualisation as an aid to analysis Collaborative working Dissemination of information Visualisations are a vital means of disseminating information to a wider audience. As some artefacts may be contested, especially where claims are being made for early evidence of lithic technology, there is an obvious issue of trust. Issues of time, affordability and access to equipment and expertise also play a key role in influencing which techniques are chosen. A combination of interviews and case studies were used to investigate how various visualisation techniques (traditional illustration, micro-CT, PTM) fulfil the requirements of lithic specialists. A new study was carried out in which a range of “difficult” artefacts were visualised using both traditional techniques and micro-CT. The results are discussed from the perspective of the end user, in this case the lithic specialist, and thus provide a novel viewpoint which should be of interest to lithic specialists, cultural heritage professionals and those engaged in developing digital techniques. [1] Parfitt S.A. et al. (2010) Nature 466, 229–233 [2] Abel, R.L., et al. (2011) Computers & Graphics 35, 878–884