606 QUANTIFYING THE HORIZONTAL-VERTICAL ILLUSION

This program allows the classical psychophysical methods of adjustment, limits, and constant stimuli to be used to determine the value of the point of subjective equality, constant error, difference limen, and interval of uncertainty for the Horizontal-Vertical Illusion. Beginning with a display which allows modification of the experimental parameters, the system presents and times the trials, records and instantly analyzes the data statistically, and displays the results at the end of the experiment or allows the data to be stored on a data disk. Instructions describe how the experiment works and how to make changes in various aspects of the experiment.