Climbability

In one of the classic investigations of affordances, Warren (1984)found that different people judged whether they could sit on a surface according to whether its height exceeded 88 percent of their leg length.a Warren, W.H., Jr.(1984). Perceiving affordances: Visual guidance of stair climbing. Journal of Experimental Psychology: Human Perception and Performance, 10, 683-703.

aWarren calculated leg length by subtracting a person's height when sitting from his or her height when standing.

 Later authors have augmented Warren's classic work, taking into consideration other variables that permit people to match their ability to act with those actions that the environment affords them. Mark (1987) found that people choose to climb or sit on a surface according to the relationship between the surface's height and their "eyeheight." Meeuwsen (1991) and Konczak and his colleagues (1992) found that aging adults judge "climbability" using an "intrinsic metric" based on body dimension, but also employ personal perceptions of strength and flexibility.

Konczak, J., Meeuwsen, H.J., & Cress, M.E. (1992). Changing affordances in stair climbing: The perception of maximum climbability in young and older adults. Journal of Experimental Psychology: Human Perception & Performance, 18, 691-7.

Mark, L. S. (1987). Eye-height-scaled information information about affordances: A study of sitting and stair-climbing. Journal of Experimental Psychology: Human Perception and Performance,13, 361-370.

Meeuwsen, H.J. (1991). Variables affecting perceptual boundaries in bipedal stair climbing. Perceptual & Motor Skills, 72, 539-43.

Last updated 1-28-99 Dave Thompson PT