Ames window

[1] During the 1960s, the concept of "transactional ambiguity" was studied and promulgated by some psychologists based on the use of the Ames Window.

[citation needed] The Ames Window was used in experiments to test this hypothesis by having subjects look through a pinhole to view the rotating window with a grey wooden rod placed through one pane at an oblique angle.

Subjects were divided into two experimental groups; one told that the rod was rubber and the other that it was steel.

These experiments were popular in university experimental psychology courses, with results sometimes supporting the hypothesis while other times not.

Although literature describing "transactional ambiguity" and the hypothesis of the perceptual effect of mental set has largely disappeared from the scene, it remains an interesting and provocative use of the visually ambiguous demonstrations for which Ames was well known, and if true provides additional scientific foundation for the "eye witness" phenomenon well known in law enforcement and research circles.