  This study presents insights from interviews with nineteen Knowledge Graph
(KG) practitioners who work in both enterprise and academic settings on a wide
variety of use cases. Through this study, we identify critical challenges
experienced by KG practitioners when creating, exploring, and analyzing KGs
that could be alleviated through visualization design. Our findings reveal
three major personas among KG practitioners - KG Builders, Analysts, and
Consumers - each of whom have their own distinct expertise and needs. We
discover that KG Builders would benefit from schema enforcers, while KG
Analysts need customizable query builders that provide interim query results.
For KG Consumers, we identify a lack of efficacy for node-link diagrams, and
the need for tailored domain-specific visualizations to promote KG adoption and
comprehension. Lastly, we find that implementing KGs effectively in practice
requires both technical and social solutions that are not addressed with
current tools, technologies, and collaborative workflows. From the analysis of
our interviews, we distill several visualization research directions to improve
KG usability, including knowledge cards that balance digestibility and
discoverability, timeline views to track temporal changes, interfaces that
support organic discovery, and semantic explanations for AI and machine
learning predictions.
