  This paper provides a framework for evaluating creativity in co-creative
systems: those that involve computer programs collaborating with human users on
creative tasks. We situate co-creative systems within a broader context of
computational creativity and explain the unique qualities of these systems. We
present four main questions that can guide evaluation in co-creative systems:
Who is evaluating the creativity, what is being evaluated, when does evaluation
occur and how the evaluation is performed. These questions provide a framework
for comparing how existing co-creative systems evaluate creativity, and we
apply them to examples of co-creative systems in art, humor, games and
robotics. We conclude that existing co-creative systems tend to focus on
evaluating the user experience. Adopting evaluation methods from autonomous
creative systems may lead to co-creative systems that are self-aware and
intentional.
