Complexity of architectural silhouettes: from vague impressions to definite design features

Nine 2-dimensional shapes were created that varied in four geometric factors: number of vertexes, symmetry, variation of lengths of line segments, and variation of angles. The shapes were evaluated in a paired-comparison experiment on the criterion of perceived complexity. Analysis of variance suggested that the most important predictor of shape complexity was the number of vertexes. P2/A (perimeter squared divided by the area) was also strongly correlated with judged complexity. Symmetry was a significant but weak predictor of complexity.