Cain’s house revisited and revived: extending theory and methodology for quantifying drawing accuracy

In 1943 Theron Cain studied art students’ ability to draw a series of simple two-dimensional shapes, and found this ability to be correlated with formal drawing assessments at art school. This provided evidence that some aspects of drawing ability could be quantified, and that performance on simple drawing tasks could predict higher level attainment. The current study sought to validate Cain’s findings by exploring the validity of shape analysis techniques for measuring drawing accuracy and by measuring reproduction of angles and proportions in a rendering and nonrendering task. Drawing accuracy derived from shape analysis methods was found to be correlated with subjective rating scores of accuracy. Subjective ratings were based upon holistic shape attributes for organic stimuli, and local shape attributes for geometric stimuli. The ability to represent simple angular and proportional relationships also related to higher level drawing ability in both rendering and nonrendering scenarios. These findings provide support for both the methodological approach and the theoretical implications of Cain’s early empirical study into observational drawing accuracy.