Readability of Digital Display

Abstract

 Digital display has been widely used as visual aids nowadays to enhance learning. Visual aids enhance the audience engagement and learning experience. However, it can turn into a source of distraction or annoyance if not used properly. Luminance and chromatic contrast can impact the visibility, legibility, and readability of the digital display. This study aims to provide a better understanding of the illumination setting of digital display and its impact on the learner’s readability at a six meters’ viewing distance. Methods: The background illumination for Microsoft Office PowerPoint was pre-set at one-quarter (25%), half (50%), three-quarter (75%), and full (100%) transparency levels in the legibility investigation. Four texts were constructed with the same word count of sixty-three words and four to twelve related words per sentence. The font, colour, alignment of the texts were standardized. Readability was inferred from the reading speed measurement to complete a digital text display projected at six meters. Results: Variation in reading performance was found at the viewing distance of six meters (F=2.83, p<0.05). Readability was significantly affected by different background illumination settings. It was interesting to unearth that the optimum readability was at 75% transparency level, but not in a complete transparency setting. Conclusions: It is generally accepted that high luminance contrast enhances visibility and legibility. Optimum readability at a three-quarter transparency level found in our study has prompted the need for further contrast investigation on the relationship between visibility, legibility and readability in different durations of digital display exposures.