  Prewriting is the process of discovering and developing ideas before a first
draft, which requires divergent thinking and often implies unstructured
strategies such as diagramming, outlining, free-writing, etc. Although large
language models (LLMs) have been demonstrated to be useful for a variety of
tasks including creative writing, little is known about how users would
collaborate with LLMs to support prewriting. The preferred collaborative role
and initiative of LLMs during such a creativity process is also unclear. To
investigate human-LLM collaboration patterns and dynamics during prewriting, we
conducted a three-session qualitative study with 15 participants in two
creative tasks: story writing and slogan writing. The findings indicated that
during collaborative prewriting, there appears to be a three-stage iterative
Human-AI Co-creativity process that includes Ideation, Illumination, and
Implementation stages. This collaborative process champions the human in a
dominant role, in addition to mixed and shifting levels of initiative that
exist between humans and LLMs. This research also reports on collaboration
breakdowns that occur during this process, user perceptions of using existing
LLMs during Human-AI Co-creativity, and discusses design implications to
support this co-creativity process.
