Note on the optimal length for visual interpolation.

When Ss were required to interpolate a scale division into tenths, Churchill was unable to confirm the "law" of constant visual angle. In this his result disagrees with other research on interpolation into fifths, which has become the basis of a forthcoming British Standard Institution recommendation. Dial designs based on the BSI recommendation have been validated on the shop floor. Possible causes for the difference in findings are discussed. From Psyc Abstracts 36:05:5LK41M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)