Quantitative Analysis of Coins as Size Reference

Coins are used for size comparison in photographs. This interdisciplinary study compiles a comprehensive dataset of over 1000 instances where coins are utilized as size references in scientific publications. Employing quantitative analysis, a numismatic measurement system is uncovered that is characterized by widespread adoption and discernible conventions governing coin use. The findings are presented in this article. The analysis reveals a prototypical numismatic measurement system with widespread use and distinguishable rules on how coins get used. The prevalence of coins as a size reference is within the single-digit percentage range in several technical journals. Distributions examine the number of coins per article and explore correlations of coins by number of pages, figures, and photographs. Text analysis reveals the authors’ deliberate choice to use coins for scale and size comparison. Coins lack many aspects of modern measurement tools. They are not used as a measurement unit unlike the meter or the inch and they do not provide a lower and upper bound on size. The dataset provides evidence that coins are used as a size reference for objects with similar dimensions and are occasionally used in conjunction with other measurement tools. Coin properties other than their size are not widely used for measurement applications. A numismatic analysis provides statistics of used currencies, denominations, and mint years. Analysis reveals a trend toward larger currencies when using foreign coins, but generally, coins are chosen from the first author’s country. Similar items like banknotes, credit cards, or jewelry are not used. The investigation extends to the arrangement of scenes, whether they are placed next to objects or on them, the displayed sides, and whether they are standing or lying horizontally. The study concludes by discussing notable outliers within the dataset.