  General purpose AI, such as ChatGPT, seems to have lowered the barriers for
the public to use AI and harness its power. However, the governance and
development of AI still remain in the hands of a few, and the pace of
development is accelerating without a comprehensive assessment of risks. As a
first step towards democratic risk assessment and design of general purpose AI,
we introduce PARTICIP-AI, a carefully designed framework for laypeople to
speculate and assess AI use cases and their impacts. Our framework allows us to
study more nuanced and detailed public opinions on AI through collecting use
cases, surfacing diverse harms through risk assessment under alternate
scenarios (i.e., developing and not developing a use case), and illuminating
tensions over AI development through making a concluding choice on its
development. To showcase the promise of our framework towards informing
democratic AI development, we run a medium-scale study with inputs from 295
demographically diverse participants. Our analyses show that participants'
responses emphasize applications for personal life and society, contrasting
with most current AI development's business focus. We also surface diverse set
of envisioned harms such as distrust in AI and institutions, complementary to
those defined by experts. Furthermore, we found that perceived impact of not
developing use cases significantly predicted participants' judgements of
whether AI use cases should be developed, and highlighted lay users' concerns
of techno-solutionism. We conclude with a discussion on how frameworks like
PARTICIP-AI can further guide democratic AI development and governance.
