Public trust in science and scientists underlies many of the contentious questions in public engagement. Two articles in this issue probe how it underpins some current problems.
The US National Science Advisory Board for Biosecurity decided in March to publish the full text of scientific papers on the avian flu virus H5N1. It had been genetically modified to be transmissible between ferrets: a model for mammals. The decision followed agonized balancing of the danger that full publication would hand useful data to biological terrorists, against the scientific imperative for freedom of information. On p19, Matthias Kaiser unpicks the complex of problems lying behind the issue. He concludes that larger segments of the public need to be involved in drawing up a voluntary code to be adopted by the scientists. This would ‘build up the trust that those who actively engage in this research do so fully aware of their social responsibility and are enforcing an internal security culture.’
Jerome Ravetz  points to a different aspect of public trust in scientists, which he calls the Burns’s louse insight. Scientists are committed to telling the complicated truth; but to alert the public to, for example, climate change, they need the media with its uncomplicated messages. The temptation to sound certain can result in their making statements later shown to be wrong. But what does the public think of scientists who speak with forked tongues? Scientists need to ‘see ourselves as others see us’, says Ravetz. Unsupportable statements damage public trust in science more than an open admission of ignorance and uncertainty.
Both Eric Hoffman  and Jack Stilgoe  write about the governance of science. Hoffman is concerned that synthetic biology be carried out in the public interest, and lays out principles that research should follow to ensure that it is. Stilgoe explains the latest thinking behind responsible innovation. Instead of assuming that the public is somehow the problem, responsible innovation asks scientists, funders and regulators to answer questions about how innovation is governed, who is responsible and what the alternatives might be.
Meanwhile, Oliver Escobar  discerns that the role of public engagement practitioners is becoming more political, and advocates training that recognizes this and equips them with ‘skills and tools to work the spaces of power’.
Our last pre-Olympic issue could hardly ignore the approach of London 2012. The spat  pits Jim Parry and Steve Haake against each other in a debate about whether the use of technology in sport is cheating. And Joanna Carpenter  looks at how sport is being used as a tool for public engagement.
Finally, the Exchange relates some rare admissions: failures in public engagement. Steve Cross, Karen Bultitude and Daniel Glaser all confess that their endeavours have not always been successful, and urge others to be more honest in a common attempt to understand the problems and get to grips with them.