¹Nossal Institute for Global Health, University of Melbourne, Victoria, Australia

Correspondence: Rob Moodie, The Nossal Institute of Global Health, University of Melbourne, Level 5, Alan Gilbert Building, Victoria 3010, Australia. E-mail: r.moodie@unimelb.edu.au

Evidence is a necessary but not sufficient element of good policy.

In 2003 in Melbourne, Australia, several key thinkers, policy makers, and advocates interested in decreasing violence against women got together with a group of researchers. They wanted to know the magnitude of the problem and its impact on women's health. They worked together, the researchers explaining the methodologies and the limitations of the results and the policy makers refining the questions they needed solved.

Twelve months later they got the shocking answer: that violence against women is the largest cause of preventable illness in adult women (1, 2). This piece of work has had a major impact on providing considerably more planning and resources to programs for reducing violence against women.

Down the road from my office, researchers at the Cancer Council have a long tradition of providing leads for legislative and regulatory reform in tobacco control and for social marketing campaigns. Similarly, practitioners and advocates ask the researchers to discover the levels of community support for potential reforms – a kind of virtuous circle (3).

There is nothing more disheartening for researchers than to see their research metaphorically (and sometimes literally) thrown in the bin by politicians and senior bureaucrats. And there is nothing more frustrating for policy makers to spend time reading through an article to find they are either unable to understand it or that the only conclusion of a piece of research is that "we need more research."

But get the combination right and researchers can have major impacts on policy and programs. For example, over a 4-year period in India, the Gates Foundation-funded Avahan program disseminated a major HIV prevention program across 600 sites that reached 300,000 sex workers, 20,000 injecting drug users, and 50,000 men who have sex with men. The program is built at every stage on research, documentation, and dissemination (4). Quantitative and qualitative research are fundamental to the program and they bring change to program strategy and approach on the basis of the evidence collected.

The Avahan program, including its partner researchers, has influenced national and state governments so profoundly that it is being handed over to its "rightful" owners – governments, non-governmental organizations, and communities – over the next 2–4 years.

Researchers in the field of physical activity who want to work with practitioners and to influence policy will have to follow some relatively universal rules about practitioners and policy makers.

1. Remember that you are working with people! Establish respectful relationships based on trust, open communication, and a sense of mutual obligation. Always publicly acknowledge your relationship with them (and hopefully their support).
2. Learn about their world. Try to see the world through their eyes, so you can understand what is important to them. What do their jobs involve, what makes them tick, and where do they fit in the chain of command, be it bureaucratic or political?
3. Try to speak their "language" and don't expect that they will understand yours. Write for them rather than for your fellow researchers. A number of the abstracts of the articles in this supplement would not be easily comprehensible to policy makers or practitioners. The abstract may be all that a policy maker has time to read or interest to do so. Abstracts are often written for an audience of other researchers; they may be too technical and rely too much on assumed knowledge, or they may be unclear in their conclusions and basic message. An additional "plain language" abstract designed for the policy maker/practitioner may be of great use.
4. Learn about the needs of practitioners and policy makers. What are the crucial questions they need answered? These may not necessarily be the questions you are interested in, but if you want the interest of your intended audience, you will have to think about your audience's needs. For example, do practitioners and policy makers need to know about:
   • Causation (e.g., the role of density, access to public open space, and access to mixed land use in increasing physical activity)?
   • The trends over time (e.g., changes in children's active travel patterns)?
   • Levels of community opinion regarding current or planned policies (e.g., attitudes to increasing density or traffic management to slow traffic or reduce exposure to traffic in residential areas)?
   • Evidence from past policies or past investments? (see, e.g., Raczynski et al. (5) and Belansky et al. (6) in this supplement.)
   • How to implement a program?
   • The impact of an environmental change policy?
   • What are the "best buys" or most promising interventions?
5. Find out whom policy makers or practitioners need to convince, so you can provide the argument(s) they need. For example, do they need to convince the bureaucratic chief(s) such as the head of department, or a majority of senior departmental executives? Do they have to convince the Minister, or other senior politicians; or the Ministerial Cabinet or a Cabinet sub-committee? Do the politicians in turn have to convince the community (the voters) or powerful vested interests?
6. Establish your common ground or common interests. What can policy makers and practitioners do for you and what can you do for them? If you want to influence policy makers, get them involved early, preferably through supporting your research, or by being on a steering committee, or by informing them as you go along.
   Some tips:
   • If you don't ask, people can't say yes!
   • Be patient and persistent.
   • Try humility – it often works.
   • Don't be discouraged or put off.
   • Be very clear in what you are requesting.
   • Use all the "connections" you have.
   • Be concise.

Don't expect that policy makers MUST listen to your research evidence because it is correct! For example, your evidence may not be of interest in the current (political) climate, it may be contested evidence, or its implementation may be impractical politically, financially, or otherwise right now. You may have to wait for a change of government or for the key bureaucrat to move. It can be very hard to get decision makers interested in the environmental determinants of physical activity if they believe that personal responsibility determines all behaviour. But to repeat – be patient and persistent!

As a researcher trained in the logic of scientific research you might have to learn new skills: the art of diplomacy and the tactics of influence. You have to know about the prevailing philosophies and ideologies of those you are trying to influence. Get advice from others, learn from those who do this well. Seek mentors. You might have to do some of your own research to learn how to make your research have a greater impact.