Shape-slant relations under reduction conditions

Two experiments are reported which attempted to test implications of the shape-slant invariance hypothesis. Both experiments employed an apparatus in which variations in the slant and in the width settings of a rectangle were highly ambiguous and subject to instructional sets. In the first experiment, the stimulus was varied in both its width and its slant to achieve matches to four standard angles; the resultant width settings were found to be close to the projected widths of the obtained angles of slant. In the second experiment, width and slant were varied to match four standard widths; the projected widths of the obtained angles of slant did not differ from the obtained width settings.