How do typographical factors affect reading text and comprehension performance in Arabic?

Objective: The objective of this study was to establish basic reading performance that could lead to useful design recommendations for print display text formats and layouts for the improvement of reading and comprehension performance of print text, such as academic writings, books, and newspapers, of Arabic language. Background: Readability of English print text has been shown to be influenced by a number of typographical variables, including interline spacing, column setting and line length, and so on. Therefore, it is very important to improve the reading efficiency and satisfaction of print text reading and comprehension by following simple design guidelines. Most existing research on readability of print text is oriented to build guidelines for designing English texts rather than Arabic. However, guidelines built for English script cannot be simply applied for Arabic script because of orthographic differences. Method: In the current study, manipulating interline spacing and column setting and line length generated nine text layouts. The reading and comprehension performance of 210 native Arab students assigned randomly to the different text layouts was compared. Results: Results showed that the use of multicolumn setting (with medium or short line length) affected comprehension achievement but not reading and comprehension speed. Participants' comprehension scores were better for the single-column (with long line length) than for the multicolumn setting. However, no effect was found for interline spacing. Conclusion: The recommendations for appropriate print text format and layout in Arabic language based on the results of objective measures facilitating reading and comprehension performance is a single-column (with long line length) layout with no relevance of the interline spacing.