The need for policy makers to understand science and for scientists to understand policy processes is widely recognised. However, the science-policy relationship is sometimes difficult and occasionally dysfunctional; it is also increasingly visible, because it must deal with contentious issues, or itself becomes a matter of public controversy, or both. We suggest that identifying key unanswered questions on the relationship between science and policy will catalyse and focus research in this field. To identify these questions, a collaborative procedure was employed with 52 participants selected to cover a wide range of experience in both science and policy, including people from government, non-governmental organisations, academia and industry. These participants consulted with colleagues and submitted 239 questions. An initial round of voting was followed by a workshop in which 40 of the most important questions were identified by further discussion and voting. The resulting list includes questions about the effectiveness of science-based decision-making structures; the nature and legitimacy of expertise; the consequences of changes such as increasing transparency; choices among different sources of evidence; the implications of new means of characterising and representing uncertainties; and ways in which policy and political processes affect what counts as authoritative evidence. We expect this exercise to identify important theoretical questions and to help improve the mutual understanding and effectiveness of those working at the interface of science and policy.

Public policy requires public support, which in turn implies a need to enable the public not just to understand policy but also to be engaged in its development. Where complex science and technology issues are involved in policy making, this takes time, so it is important to identify emerging issues of this type and prepare engagement plans. In our horizon scanning exercise, we used a modified Delphi technique [1]. A wide group of people with interests in the science and policy interface (drawn from policy makers, policy adviser, practitioners, the private sector and academics) elicited a long list of emergent policy issues in which science and technology would feature strongly and which would also necessitate public engagement as policies are developed. This was then refined to a short list of top priorities for policy makers. Thirty issues were identified within broad areas of business and technology; energy and environment; government, politics and education; health, healthcare, population and aging; information, communication, infrastructure and transport; and public safety and national security.

In 1971, (Lord) Victor Rothschild, reported to Government on "The Organisation and Management of Government R&D" and how government could become (in his words) a customer for research contracted from the Research Councils and other sources. Rothschild's thinking implied that management of R&D by "customer" Departments would bring an understanding of research outputs. He proposed the transfer of applied science funds from Research Councils to Government Departments, providing each with a Chief Scientist as proxy customer for research to be commissioned on a "customer/contractor" basis. The Government largely adopted his proposals in 1972 and implemented them in 1974. The Rothschild reforms and the upheavals they brought were controversial at the time, though now in some instances, reversed and otherwise either forgotten or buried in unconscious assumptions. However, the Rothschild framework still underpins important assumptions about Departmental relationships with the science community, which in my view adversely affected the access of Government to expert advice. From the viewpoint of a participant in Government R&D management through this period, I explore the immediate response and the post-1980 history of the Rothschild reforms, discuss the way in which research commissioning became such a heavy task as to impede analysis and advice delivery, and consider alternative approaches, such as the "science broker" model. This article is published as part of a collection on scientific advice to governments.

In 1971 Lord (Victor) Rothschild published his report for the government, The organisation and management of government R&D, and Sir Peter Medawar launched a campaign for the election of Sir Karl Popper to Fellowship of the Royal Society. We explore these two developments in the contexts of the then current views of the role and purpose of science, and their underpinning philosophy. Although the political battle was won by Rothschild, resulting in major changes to the funding and management of applied R&D, we argue that, despite this, Medawar's campaign for Popper provided an embattled science community with a philosophical basis for defending pure research and the unity of basic and applied science.