A new method for accurately and precisely measuring flake platform area
A new method for accurately and precisely measuring flake platform area
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一种准确测量片状平台面积的新方法
DOI：
10.1016/j.jasrep.2016.06.015
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
C. Clarkson
中科院分区：
文献类型：
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作者：
Antoine Muller;C. Clarkson
使用3D扫描来测量平台尺寸非常准确和精确，并已用于估计岩屑组合的还原强度。虽然使用3D扫描来测量石器文物仍然是考古学的最佳实践，但在现实世界的考古场景中很少使用3D扫描技术。时间限制、预算限制、样本量大、野外工作地点偏远、电力供应不可靠以及原材料类型不合适，这些都使3D扫描变得不可行。在这种情况下，平台的大小通常是通过将平台宽度和厚度的卡尺测量值相乘来估计的，形成平台的矩形近似值。由于很少有平台像矩形，我们发现这种平台测量方法大约是真实平台尺寸的两倍，而且既不准确也不精确。为了纠正这种高估，本文介绍并测试了平台的几何近似（GAP）方法，其中使用简单的二维形状（三角形，菱形，梯形和椭圆）来支持当前使用的矩形近似。与平台宽度和厚度测量相比，GAP方法是一种简单易行的方法，可以显著提高平台测量的准确度和精度，与3D扫描的平台面积值在统计上无法区分。此外，我们提供了一种方法，通过该方法可以将平台宽度和厚度值转换为与GAP方法获得的值一起使用，这意味着使用GAP方法与先前分析的组合进行站点间比较不会受到阻碍。
The use of 3D scanning to measure platform size is remarkably accurate and precise and has been used to estimate reduction intensity in lithic assemblages. While using 3D scans to measure lithic artefacts remains best practice in archaeology, the use of 3D scanning technology is seldom possible in real-world archaeological scenarios. Time constraints, budgetary constraints, large sample sizes, remote fieldwork locations, unreliable access to electricity and unsuitable raw material types can render 3D scanning unfeasible. In such scenarios, platform size is typically estimated by multiplying calliper measurements of platform width and thickness, forming a rectangular approximation of the platform. As few platforms resemble rectangles, we find that this method of platform measurement approximately doubles true platform size and is neither accurate nor precise. To remedy this overestimation, this paper introduces and tests the Geometric Approximations of Platforms (GAP) method, where simple 2D shapes (triangle, rhombus, trapezoid and ellipse) are employed in favour of the currently used rectangular approximations. Compared with platform width and thickness measurements, the GAP method is an equally simple and easily applied method that significantly increases both the accuracy and precision of platform measurements, being statistically indistinguishable from 3D scanned platform area values. Moreover, we offer a means by which platform width and thickness values can be converted to be used in conjunction with those obtained from the GAP method, meaning that inter-site comparisons with previously analysed assemblages would not be hindered for those employing the GAP method.