Abstract—Traditionally, information visualization research tends to focus only on performance related metrics such as task completion time and correctness. However, a recent interest on goals such as memorability, engagement, and fun has also sparked. We propose a reflection on visualization assessment supported by a profound analysis of research that includes user studies of visualization tools and techniques. The motivation for this study is to explore the possible benefits of having a unified standardized metric for usability and user experience that can become a clearer quantitative model of both. Such a metric can provide visualization researchers and practitioners a more succinct and accurate way to assess their visualizations.