Effects of Two Type Density Characteristics on the Legibility of Print

Abstract

A great deal of research exists regarding the likelihood that warning information will be noticed, but much less research has examined the conditions under which warnings are likely to be read. One variable that may influence the ability and willingness of people to read text is legibility. Poor legibility may result in the information being more difficult to read and thus be a deterrent to reading it. An important determinant of legibility is print density. The present study examined the effect of two print density manipulations, type width and inter-character spacing, on the ease with which warnings could be read. Subjects selected the more “readable” of two choices in a paired comparison task involving all possible combinations of type width (35% of normal, 60% of normal and 100%) and inter-character spacing (10% of normal, 50% and 90%). Results demonstrated that subjects preferred the 100% type width followed by the 60% and then the 35% widths. There was no main effect of inter-character spacing, although spacing did interact with type width. In a subsequent reading-speed task, it was shown that, the smallest print condition (with the 35% width and 10% inter-character spacing) produced significantly longer reading times than either the intermediate or larger print conditions. Overall, these results suggest that type width is a strong determinant of print legibility, and that it can be manipulated to increase the ease with which warning information is accessed.