An Empirical User Study for Measuring the Influence of Colour Distance and Font Size in Map Reading Using Eye Tracking

Abstract

The primary goal of this study is to empirically analyse the influence of colour distance and font size on map readability. We utilized eye-tracking to complement the classical usability metrics; thus, we studied performance metrics such as effectiveness (i.e. success, accuracy), efficiency (i.e. time to answer, task completion time), and selected eye tracking metrics fixation frequency, fixation duration and scanpath speed as well as conducting an area-of-interest (AOI) analysis to understand the performance and strategy issues that may be influenced by colour distance and font size during map reading. The user experiment was carried out in a controlled laboratory where participants were asked to conduct a visual search task and mark the correct answer with a mouse click on a static map on a computer screen. Collected data was analysed through descriptive and inferential statistics. Task completion times for the five tested colour distances show that as the colour distances grow larger, the relative differences in task completion times become statistically significant; empirically confirming our intuition that larger colour distances are better for map readability. The comparison of the scanpath speeds for the tested font sizes suggests that the medium font size leads to a more efficient search.