Are two spaces better than one? The effect of spacing following periods and commas during reading

Abstract

The most recent edition of the American Psychological Association (APA) Manual states that two spaces should follow the punctuation at the end of a sentence. This is in contrast to the one-space requirement from previous editions. However, to date, there has been no empirical support for either convention. In the current study, participants performed (1) a typing task to assess spacing usage and (2) an eye-tracking experiment to assess the effect that punctuation spacing has on reading performance. Although comprehension was not affected by punctuation spacing, the eye movement record suggested that initial processing of the text was facilitated when periods were followed by two spaces, supporting the change made to the APA Manual. Individuals' typing usage also influenced these effects such that those who use two spaces following a period showed the greatest overall facilitation from reading with two spaces.

Visual-Syntactic Text Format: Improving Adolescent Literacy

“…Another approach to making texts more accessible for diverse and struggling readers is by adjusting the print itself. These alterations have taken the form of simple changes in letters, spacing between lines and sentences, or capitalization (Johnson, Bui, & Schmitt, 2018), or the insertion of additional spaces between phrases (Bever, Jandreau, Burwell, Kaplan, & Zaenen, 1990;Hirotani et al, 2006;Jandreau & Bever, 1992). Although a number of studies found that print modifications may support English learners' understanding of English texts (Lee, 2007;Lee & Huang, 2008;Shook, 1994;Simard, 2009), others reported that simple print modifications, such as underlined and bold letters, may have little or no effect on language learning (Leow, 1997;Overstreet, 1998).…”