Related studies Sentence spacing studies

an example of river effect in justified text

david jury s book, typography? notes following: changes in spacing either between letters , words, or between words only ... not appear affect legibility. [these rather extraordinary conclusions contrary other surveys on readability of texts.]

a widespread observation increased sentence spacing creates rivers or holes within text, making visually unattractive, distracting, , difficult locate end of sentences. comprehensive works on typography describe negative effect on readability caused inconsistent spacing, supported in 1981 study found comprehension less accurate river condition. 1981 study on cathode ray tube (crt) displays concluded more densely packed text read more efficiently … more loosely packed text. statement supported in other works well. canadian typographer geoffrey dowding suggests possible explanations of phenomenon:

a composed text page appears orderly series of strips of black separated horizontal channels of white space. conversely, in slovenly setting tendency page appear grey , muddled pattern of isolated spats, effect being caused over-widely separated words. normal, easy, left-to-right movement of eye slowed down because of separation; further, short letters , serifs unable discharge important function – of keeping eye on line . eye tends confused feeling of vertical emphasis, is, & down movement, induced relative isolation of words & consequent insistence of ascending , descending letters. movement further emphasized rivers of white inseparable & ugly accompaniment of carelessly set text matter.

some studies suggest readability can improved breaking sentences separate units of thought—or varying internal spacing of sentences. mid-20th century research on topic resulted in inconclusive findings. 1980 study split sentences 1–5 word phrases additional spacing between segments. study concluded there no significant difference in efficacy, wider study needed. numerous other similar studies in 1951–1991 resulted in disparate , inconclusive findings.

finally, although various studies have been conducted on readability of proportional vs. monospaced fonts, studies typically did not decrease sentence spacing when using proportional fonts, or did not specify whether sentence spacing changed.