Graduate Research and Discovery Symposium (GRADS)

Document Type


Publication Date

Spring 2015


The purpose of this experiment was to investigate whether people were able to accurately judge their ability to traverse a gap. Additionally, we also observed if participants exhibited amargin of safety in their judgments when more than one action was possible. Affordances are features of the environment and characteristics of an organism that make a particular action possible, and in terms of locomotion, it is vitally important to be able to accurately perceive affordances. In this experiment, participants were asked to judge whether a gap afforded traverse-ability. Participants were split into three groups (focal, timed, and embedded) to investigate how varying constraints on the task affected perception of affordances. Participants gave a judgment for 36 randomized distances about whether or not they could cross the gap, whether they would step or leap over the gap, and how safe it would be to perform that action on a 7-point scale. We found that participants exhibited a margin of safety in their judgments when the perception-action task was preserved. We also found that participants were able to recognize when gap length surpassed their actual maximum stepping ability and exhibited a concurrent increase in safety ratings as a result.