Readability of Typewritten Material: Proportional Versus Standard Spacing

Abstract

To what extent do differences in the spacing and width of characters affect the readability of typewritten materials? Reading speed and comprehension scores were compared in two studies; an original experiment and a subsequent replication. Test material consisted of several passages taken from the Davis Reading Test andtyped in two versions-one set with proportional spacing (IBM Modern) and the other with standard spacing (IBM Prestige Elite). Results showed a significant difference in reading speed in favor of proportional spacing, without loss in comprehension. There was also evidence of an interaction between passage-difficulty and character spacing, which suggests that reading speed measures may underestimate real differences in readability if comparisons are based solely on simple or familiar material.