Data can be smoothed by clicking on the Filter check box. The program uses a simple averaging algorithm described by Dain and Birch (1987). Filtering can be helpful for interpreting 'noisy' data and determining an axis of confusion for color defectives.
Filtering is turned off by deselecting the check box.
Refererence
Dain, S.J. and Birch, J. (1987) An averaging method for the interpretation of the Farnsworth-Munsell 100-Hue Test - I. Congenital colour vision defects. Ophthal. Physiol.Opt., Vol 7, No. 3, pp 267-280.