Understanding which factors affect information visualization transparency continues to be one of the most relevant challenges in current research, especially since trust models how users build on the knowledge and use it. This work extends the current body of research by studying the user’s subjective evaluation of the visualization transparency of hierarchical charts through the clarity, coverage, and look and feel dimensions. Additionally, we extend the user profile to better understand whether personality facets manifest a biasing effect on the trust-building process. Our results show that the data encodings do not affect how users perceive visualization transparency while controlling for personality factors. Regarding personality, the propensity to trust affects how they judge the clarity of a hierarchical chart. Our findings provide new insights into the research challenges of measuring trust and understanding the transparency of information visualization. Specifically, we explore how personality factors manifest in this trust-building relationship and user interaction within visualization systems.

Recent research focuses on understanding what triggers cognitive biases and how to alleviate them in the context of visualization use. Given its role in decision-making in other research fields, the Phantom Effect may hold exciting prospects among known biases. The Phantom Effect belongs to the category of decoy effects, where the decoy is an optimal yet unavailable alternative. We conducted a hybrid design experiment (N=76) where participants performed decision tasks based on information represented in different visualization idioms and phantom alternative’s unavailability presentation delays. We measured participants’ perceptual speed and visual working memory to study their impact on the expression of the Phantom Effect. Results show that visualization usually triggers the Phantom Effect, but two-sided bar charts mitigate this bias more effectively. We also found that waiting until the participant decides before presenting the decoy as unavailable helps alleviate the Phantom Effect. Although we did not find measurable effects, results also suggest that visual working memory and visualization literacy play a role in bias susceptibility. Our findings extend prior research in visualization-based decoy effects. They are the first steps to understanding the role of individual differences in the susceptibility to cognitive bias in visualization contexts. • The Phantom Effect manifests in decision-making supported by visualization. • Two-sided bar charts with an unknown presentation delay mitigate the Phantom Effect. • Better visualization literacy may increase priming by the Phantom Effect.

The impact of individual differences, such as personality traits, on user performance and human behaviors has been studied in several fields of human–computer interaction, with a growing interest in information visualization. Although most visualizations are still designed with a universal approach, great strides have been made toward the development of user-adaptive visualizations catered to the user’s personality. We analyze how personality affects user interaction with high-dimensional visualizations. Specifically, we explore the impact of neuroticism (including its facets) and locus of control in user performance and confidence. Results suggest that neurotic individuals are faster with the scatterplot matrix, while individuals with an internal locus are more confident when using the parallel coordinates plot. In addition, results indicate that the facets of neuroticism have significant – and distinct from neuroticism – impact on user performance and confidence, pointing toward the need to analyze traits, such as neuroticism, at a lower level.

Throughout the years, social norms have been promoted as an informal enforcement mechanism for achieving beneficial collective outcomes. Among the most used methods to foster interactions, framing the context of a situation or setting in-game rules have shown strong results as mediators on how an individual interacts with their peers. Nevertheless, we found that there is a lack of research regarding the use of incentives such as scores to promote social interactions differing in valence. Weighing how incentives influence in-game behavior, we propose the use of rewards to promote interactions varying in valence, i.e. positive or negative, in a two-player scenario. To do so, we defined social valence as a continuous scale with two poles represented by Complicate and Help. Then, we performed user tests where participants where asked to play a game with two reward-based systems to test on whether the scoring system influenced the social interaction valence. The results indicate that the developed reward-based systems were able to foster interactions diverging in social valence scores, providing insights on how factors such as incentives overlap individual’s established social norms. These findings empower game developers and designers with a low-cost and effective policy tool that is able to promote in-game behavior changes.