“…In all cases, the reversals change the meaning of the figure. We did not select figures like the Necker cube (Necker, 1832) that involved fluctuations in depth, and when possible, we tried to stay away from classic figures like Boring's wife/mother-in-law figure (Boring, 1930) or the face/vase (Rubin, 1958) that are so familiar to students. Because knowledge of an alternative interpretation of the figures has been shown by Rock and his colleagues (Girgus, Rock, & Egaz, 1977;Rock & Mitchener, 1992) to be an important aspect to seeing the reversal, we tried to use figures that were not widely distributed.…”