Dark Mode or Light Mode? Exploring the Impact of Contrast Polarity on Visualization Performance Between Age Groups

TL;DR

This study investigates how positive and negative contrast polarities in visualizations affect analysis performance across different age groups, revealing individual variability and emphasizing the need for accessible visualization options.

Contribution

It provides empirical evidence on the effects of contrast polarity on visualization performance across age groups, highlighting individual differences and the importance of dual-polarity options.

Findings

Contrast polarity benefits vary individually and do not always align with user preferences.

Contrast polarity impacts analysis time as much as visualization type, with an average difference of 36%.

Effects of contrast polarity on performance are consistent across age groups.

Abstract

This study examines the impact of positive and negative contrast polarities (i.e., light and dark modes) on the performance of younger adults and people in their late adulthood (PLA). In a crowdsourced study with 134 participants (69 below age 60, 66 aged 60 and above), we assessed their accuracy and time performing analysis tasks across three common visualization types (Bar, Line, Scatterplot) and two contrast polarities (positive and negative). We observed that, across both age groups, the polarity that led to better performance and the resulting amount of improvement varied on an individual basis, with each polarity benefiting comparable proportions of participants. However, the contrast polarity that led to better performance did not always match their preferred polarity. Additionally, we observed that the choice of contrast polarity can have an impact on time similar to that of the choice of visualization type, resulting in an average percent difference of around 36%. These findings indicate that, overall, the effects of contrast polarity on visual analysis performance do not noticeably change with age. Furthermore, they underscore the importance of making visualizations available in both contrast polarities to better-support a broad audience with differing needs. Supplementary materials for this work can be found at https://osf.io/539a4/.