  Many researchers studying online communities seek to make them better.
However, beyond a small set of widely-held values, such as combating
misinformation and abuse, determining what 'better' means can be challenging,
as community members may disagree, values may be in conflict, and different
communities may have differing preferences as a whole. In this work, we present
the first study that elicits values directly from members across a diverse set
of communities. We survey 212 members of 627 unique subreddits and ask them to
describe their values for their communities in their own words. Through
iterative categorization of 1,481 responses, we develop and validate a
comprehensive taxonomy of community values, consisting of 29 subcategories
within nine top-level categories, enabling principled, quantitative study of
community values by researchers. Using our taxonomy, we reframe existing
research problems, such as managing influxes of new members, as tensions
between different values, and we identify understudied values, such as those
regarding content quality and community size. We call for greater attention to
vulnerable community members' values, and we make our codebook public for use
in future research.
