Department of Cognitive Biology, University of Vienna, Vienna, Austria.
PLoS One. 2013 Sep 16;8(9):e74055. doi: 10.1371/journal.pone.0074055. eCollection 2013.
Human artefacts in general are highly structured and often display ordering principles such as translational, reflectional or rotational symmetry. In contrast, human artefacts that are intended to appear random and non symmetrical are very rare. Furthermore, many studies show that humans find it extremely difficult to recognize or reproduce truly random patterns or sequences. Here, we attempt to model two-dimensional decorative spatial patterns produced by humans that show no obvious order. "Crazy quilts" represent a historically important style of quilt making that became popular in the 1870s, and lasted about 50 years. Crazy quilts are unusual because unlike most human artefacts, they are specifically intended to appear haphazard and unstructured. We evaluate the degree to which this intention was achieved by using statistical techniques of spatial point pattern analysis to compare crazy quilts with regular quilts from the same region and era and to evaluate the fit of various random distributions to these two quilt classes. We found that the two quilt categories exhibit fundamentally different spatial characteristics: The patch areas of crazy quilts derive from a continuous random distribution, while area distributions of regular quilts consist of Gaussian mixtures. These Gaussian mixtures derive from regular pattern motifs that are repeated and we suggest that such a mixture is a distinctive signature of human-made visual patterns. In contrast, the distribution found in crazy quilts is shared with many other naturally occurring spatial patterns. Centroids of patches in the two quilt classes are spaced differently and in general, crazy quilts but not regular quilts are well-fitted by a random Strauss process. These results indicate that, within the constraints of the quilt format, Victorian quilters indeed achieved their goal of generating random structures.
一般来说，人工制品具有高度的结构性，并且通常表现出平移、反射或旋转对称等有序原则。相比之下，旨在呈现随机和非对称外观的人工制品非常罕见。此外，许多研究表明，人类发现识别或再现真正的随机模式或序列极其困难。在这里，我们试图模拟人类产生的没有明显秩序的二维装饰空间模式。“疯狂被子”代表了一种历史上重要的被子制作风格，于 19 世纪 70 年代流行，并持续了大约 50 年。疯狂被子不同寻常，因为与大多数人工制品不同，它们特别旨在呈现出随意和无结构的外观。我们使用空间点模式分析的统计技术来评估这种意图的实现程度，将疯狂被子与同一地区和同一时期的常规被子进行比较，并评估各种随机分布对这两种被子类型的拟合程度。我们发现这两种被子类别表现出根本不同的空间特征：疯狂被子的补丁区域源自连续的随机分布，而常规被子的面积分布由高斯混合组成。这些高斯混合来自重复的规则图案图案，我们认为这种混合是人为视觉模式的独特特征。相比之下，在疯狂被子中发现的分布与许多其他自然发生的空间模式共享。两种被子类别的补丁中心点的间隔不同，一般来说，疯狂被子而不是常规被子可以很好地拟合随机 Strauss 过程。这些结果表明，在被子格式的限制内，维多利亚时代的被子制作者确实实现了他们生成随机结构的目标。
