Dial Legibility as a Function of Scale Graduation and Dial Shape

The study of dial legibility in terms of accuracy of reading has been carried on from two approaches. In one of these the dial shape is varied, while the graduations are held constant. The other approach is to hold shape constant and to vary the number of graduations. The present study presents a combination of the two earlier approaches, with shapes and graduations both being varied. Sixty dials were presented in booklets to forty Ss, who read them to the nearest 0.1 cm. while being timed. The results indicate that in dial reading situations where exposure time is not limited there is a significant difference among graduations but not among dials