What are the roles of scientists and journalists as “custodians of the knowable” and what happens when they get it wrong? How do they insulate themselves from charges of ineptness or partisanship? Kathleen Hall Jamieson, director of the Annenberg Public Policy Center, delivered the keynote lecture on Sept. 24 at the National Academy of Sciences’ second Sackler colloquium on “The Science of Science Communication.” In her talk, “Responding to the Attack on the Best Available Evidence,” and a subsequent Q&A session, Jamieson considers the roles of the scientific and journalistic communities in such hot-button issues as the effect of vaccines on autism and climate change, and offers ways in which those communities should respond to challenges to the evidence and information they disseminate. For more information on the Science of Science Communication II, click here. A video and summary of Jamieson’s talk is available here. The NAS’s Sackler Colloquia homepage is here.