Scientific uncertainty: How do we know when to communicate research findings to the public?

The problem of when to communicate research findings with the public arises with respect to a broad range of environmental and health hazards. What many people would like is a rule of the form, 'Communicate research findings if and only if condition C obtains.', where condition C reflects some function that includes the probability of a harm occurring, the seriousness of the harm, the reliability of the data on which these estimates are based, and the potential usefulness of these projections for mitigating or preventing the harm in question. I argue that no such rule is forthcoming. I go on to distinguish uncertainty from ignorance and indeterminism. Uncertainty is not an objective quantity but is socially constructed by context, rhetorical role, the assumption of purposes, and the acceptance of knowledge claims. In a particular case, the first step in deciding whether to communicate research findings to the public is appreciating how the uncertainties have been constructed. Only then can we go on to ask the ethical questions about communicating research in an illuminating way.