Proceedings of the Annual Meeting of the Cognitive Science Society

Physical constraints on growth produce continuous variations in the shape of biological objects that correspond to their sizes. We investigated whether two such properties of tree form can be visually discriminated and used to evaluate the height of trees. Observers judged simulated tree silhouettes of constant image size. Comparison was made to judgments of real trees in natural viewdng conditions. Tree form was shown to confer an absolute metric on ground texture gradients. Eyeheight information was also shown to be ineffective as an alternative source of absolute scale.