Estimating text legibility of a mobile display on the basis of translational vibration caused by walking

Abstract

— In this study, the effect of vibration on mobile-phone text legibility caused by walking was examined. Legibility was measured as reading performance and subjective task load when reading from a mobile-phone display while walking on a treadmill at 1.5 km/hour, 3 km/hour, and an individually defined speed (3.9 km/hour on average). Vibration was measured on the vertical, lateral, and fore-and-aft axes during walking. Vibration amplitude was calculated in five different frequency bands (1, 2, 4, 8, and 16 Hz), and correlated with the legibility measures. The amplitude increased most on the vertical and fore-and-aft axes as a function of walking speed, and the increase was largest in the 2-Hz frequency band. Legibility decreased concurrently with increasing vibration. The strong correlation between vibration characteristics and legibility measures suggests that vibration characteristics could, to some degree, be used in estimating small-display legibility while walking.