Web accessibility for older adults: effects of line spacing and text justification on reading web pages

Abstract

Numerous guidelines for making websites more accessible for older users have been proposed, but few provide evidence from such users for their recommendations This study investigated effects of line spacing and text justification on younger (24--31 years) and older (65--78 years) adults' performance and preferences in web reading tasks. The three levels of line spacing (single, 1.5, and double) and 2 types of text justification (left only and left-right) were studied. Neither variable had a significant effect on performance measures, although both younger and older adults preferred 1.5 or double spacing over single spacing. There were no significant differences in preferences for left versus left-right justification. These results suggest that contrary to common recommendations, 1.5 or double spacing should be recommended for all users, not only older users and that no recommendation is needed on text justification.