Making drawings speak through mathematical metrics

TL;DR

This study applies fourteen mathematical metrics to children's drawings to quantify their developmental progress in intention and representativeness, revealing three key dimensions of drawing evolution through PCA analysis.

Contribution

It introduces a novel quantitative approach using metrics and PCA to analyze developmental stages in children's drawings, differentiating between scribbles and adult drawings.

Findings

Three significant dimensions identified: efficiency, diversity, and sequentiality.

PCA explains 77% of variance in both datasets.

Metrics differentiate children's scribbles from adult drawings.

Abstract

Figurative drawing is a skill that takes time to learn, and evolves during different childhood phases that begin with scribbling and end with representational drawing. Between these phases, it is difficult to assess when and how children demonstrate intentions and representativeness in their drawings. The marks produced are increasingly goal-oriented and efficient as the child's skills progress from scribbles to figurative drawings. Pre-figurative activities provide an opportunity to focus on drawing processes. We applied fourteen metrics to two different datasets (N=65 and N=345) to better understand the intentional and representational processes behind drawing, and combined these metrics using principal component analysis (PCA) in different biologically significant dimensions. Three dimensions were identified: efficiency based on spatial metrics, diversity with colour metrics, and temporal sequentiality. The metrics at play in each dimension are similar for both datasets, and PCA explains 77% of the variance in both datasets. These analyses differentiate scribbles by children from those drawn by adults. The three dimensions highlighted by this study provide a better understanding of the emergence of intentions and representativeness in drawings. We have already discussed the perspectives of such findings in Comparative Psychology and Evolutionary Anthropology.