The Comparability of Typographic and Substrate Characteristics as Independent Variables in Legibility and Readability Studies: An Integrative Review

Abstract

English typographic and substrate factors (as independent variables) have been frequently linked with legibility and readability (as dependent variables) of English text in the reviewed literature. To properly establish the link of typographic and substrate factors with legibility and readability, the definitions and variables used in the reviewed studies should be comparable. However, from an integrative review of eighty-seven scholarly sources using mixed methods, the details of the variables provided to achieve valid and reliable comparison have not been evident or have been carelessly compared. The findings showed inconsistent and inadequate details of typographic and substrate factors in both definitions and units of measurement. With these inconsistencies in variable details and no existing guidelines, it is hard to produce reliable results that can promote real progress for instructional text design comparison. In this work, the author produced recommendations and guidelines for instructional design researchers and instructional designers to enhance the comparability of the textual comparison studies in respect of definitions and measurement of typographic and substrate factors to establish the link more properly to legibility and readability. Finally, to achieve the comparability of typographic and substrate variable details, instructional design researchers and instructional designers should include essential information, such as type elements, alignment, spacing, paper or screen size, paper or screen resolution, paper properties, and white space along with other possible supplementary information.