  Feelings of something belonging to someone is called "psychological
ownership." A common assumption is that writing with generative AI lowers
psychological ownership, but the extent to which this occurs and the role of
prompt length are unclear. We report on two experiments to better understand
the relationship between psychological ownership and prompt length.
Participants wrote short stories either completely by themselves or wrote
prompts of varying lengths, enforced through word limits. Results show that
when participants wrote longer prompts, they had higher levels of psychological
ownership. Their comments suggest they felt encouraged to think more about
their prompts and include more details about the story plot. However, these
benefits plateaued when the prompt length was 75-100% of the target story
length. Based on these results, we propose prompt entry interface designs that
nudge users with soft and hard constraints to write longer prompts for
increased psychological ownership.
