  Empirical research on perception and cognition has laid the foundation for
visualization design, often yielding useful design guidelines for
practitioners. However, it remains uncertain how well practitioners stay
informed about such crucial visualization design knowledge. In this paper, we
employed a mixed-method approach to explore the knowledge gap between
visualization research and real-world design guidelines. We initially collected
existing design guidelines from various sources and empirical studies from
diverse publishing venues, analyzing their alignment and uncovering missing
links and inconsistent knowledge. Subsequently, we conducted surveys and
interviews with practitioners and researchers to gain further insights into
their experiences and attitudes towards design guidelines and empirical
studies, and their views on the knowledge gap between research and practice.
Our findings highlight the similarities and differences in their perspectives
and propose strategies to bridge the divide in visualization design knowledge.
