  Service robots are envisioned to be adaptive to their working environment
based on situational knowledge. Recent research focused on designing visual
representation of knowledge graphs for expert users. However, how to generate
an understandable interface for non-expert users remains to be explored. In
this paper, we use knowledge graphs (KGs) as a common ground for knowledge
exchange and develop a pattern library for designing KG interfaces for
non-expert users. After identifying the types of robotic situational knowledge
from the literature, we present a formative study in which participants used
cards to communicate the knowledge for given scenarios. We iteratively coded
the results and identified patterns for representing various types of
situational knowledge. To derive design recommendations for applying the
patterns, we prototyped a lab service robot and conducted Wizard-of-Oz testing.
The patterns and recommendations could provide useful guidance in designing
knowledge-exchange interfaces for robots.
