Eye Movement Measurement of Readability of CRT Displays

Abstract

Eye movement was recorded as people read texts presented on a CRT in two different spacings, two different character densities, and at five different scrolling rates. Differences in efficiency of reading single- and double-spacing were statistically significant, but were of little practical significance. Character densities of 35 characters or 70 characters per line favored the smaller-size character with respect to efficiency of reading. Comparison of scrolling rates suggested that the static page was processed more efficiently than was the page scrolled at the subject's preferred rate or at a rate 10% slower than that; pages presented faster than the preferred rate were read more efficiently. Little if any change in preferred rate occurred as a function of practice with 16 pages of text. Systems in which, by program control, text was presented at rates 10% or 20% faster than the preferred scrolling rate should lead to more efficient performance, but might create some problems of user acceptance.