Legibility of five-digit Arabic and Devanagri numerals as a function of their sizes

The purpose was to test two hypotheses: (a) Arabic numerals would be more legible than Devanagri; and (b) among all the four type sizes, 10-point printing faces would be most legible. Five-digit stimuli of four printing sizes (8-, 10-, 12-, and 14-points), printed on white cards in deep black ink, were tachistoscopically presented to 16 students (eight males, eight females) of undergraduate and graduate classes. F ratios for within points, as well as for within scripts, were significant. In all point sizes Arabic was more legible. All but two pairs of means of Arabic numerals (8- X 10-points and 10- X 12-points), but only two pairs of means (8- X 12-points and 8- X 14-points) of Devanagri numerals were significantly different from each other. Legibility scores distinctly rose with increase in sizes in both the numerals.