Ambivalent effects of display curvature on smartphone usability

The current study examined the effects of display curvature and hand length on various smartphone usability measures. In total, 20 young participants completed reading, image viewing, video watching, calling, and texting using four smartphone devices with distinct display curvatures. Diverse usability measures related to these tasks were obtained. The four curvatures (flat, horizontally convex, vertically concave, and horizontally concave) each demonstrated both beneficial and detrimental effects; however, hand size effects were non-significant across all usability measures. No single fixed display curvature was found to be beneficial across all considered smartphone usability measures, indicating multiple curvatures (e.g. combinations of flat and vertically concave curvatures) are required from a single smartphone model rather than a single fixed curvature to improve an overall smartphone usability. Such varying curvatures are feasible with bendable displays. Comprehensive usability evaluations, especially focusing on grip comfort and image distortion, are needed when applying display curvatures on small devices.