  Beliefs are not facts, but they are factive - they feel like facts. This
property is what can make misinformation dangerous. Being able to deliberately
navigate through a landscape of often conflicting factive statements is
difficult when there is no way to show the relationships between them without
incorporating the information in linear, narrative forms. In this paper, we
present a mechanism to produce maps of belief places, where populations agree
on salient features of fictional environments, and belief spaces, where
subgroups have related but distinct perspectives. Using a model developed using
agent-based simulation, we show that by observing the repeated behaviors of
human participants in the same social context, it is possible to build maps
that show the shared narrative environment overlaid with traces that show
unique, individual or subgroup perspectives. Our contribution is a
proof-of-concept system, based on the affordances of fantasy tabletop
role-playing games, which support multiple groups interacting with the same
dungeon in a controlled, online environment. The techniques used in this
process are mathematically straightforward, and should be generalizable to
auto-generating larger-scale maps of belief spaces from other corpora, such as
discussions on social media.
