11. The system of claim 10 , wherein the first attribute rating scale is measured by a distance between the positioned point and the vertical axis drawn parallel to the horizontal axis, and the second attribute rating scale is measured by a distance between the positioned point and the horizontal axis drawn parallel to the vertical axis.
10. The system of claim 9 , wherein the display surface is a rectangle defined by a horizontal axis corresponding to the first degree of freedom and a vertical axis corresponding to the second degree of freedom.