View of rotated objects. Perception & Psychophysics

(July 1998) reported on a study of how people view three- dimensional objects projected onto a rotating two- dimensional image. Each in a sample of 25 university students viewed various depth-rotated objects (e.g., a hairbrush, a duck, and a shoe) until they recognized the object. The recognition exposure time—that is, the minimum time (in milliseconds) required for the subject to recognize the object—was recorded for each object. In addition, each subject rated the “goodness of view” of the object on a numerical scale, with lower scale values corresponding to better views. The following table gives the correlation coefficient r between recognition exposure time and goodness of view for several different rotated objects:

Object r t Piano .447 2.40 Bench -.057 .27 Motorbike .619 3.78 Armchair .294 1.47 Teapot .949 14.50

a. Interpret the value of r for each object.

b. Calculate and interpret the value of r2 for each object.

c. The table also includes the t-value for testing the null hypothesis of no correlation (i.e., for testing H0: b1 = 0).

Interpret these results using x = .05.