1. Someone driving it – most successful investigations have someone – not always the person who started it – with the energy to drive it along; they can be someone who gathers information, or raises awareness, or sets challenges. If you can see that someone has this passion you are more likely to chip in yourself.?In the hospital parking revenues investigation, for example, it was the work of Matt Buck in identifying useful organisations to contact that made me and others want to contribute. If your investigation isn't working, the best thing you can do is invest some real, visible, effort into it yourself.

2. Momentum – getting some sort of results from parts of an investigation is hugely helpful in providing feedback and encouraging the investigators to carry on. These results need not be enormous: it might be putting together a patchwork of background information that raises quesetions; identifying who is responsible for the issue; getting an official knock-back; or simply setting a new challenge. If some ideas aren't working, try others – keep trying new avenues.

3. Break-down-able – investigations work well when they are broken down into lots of different, easy-to-achieve challenges. This provides lots of different ways for people to contribute. ‘When can we expect a new Birmingham Council website?’ was one very good example that accumulated a lot of momentum and evidence in a very short time through lots of different challenges. See this post and the list it includes for some ideas.

4. Being public – the more people know about an investigation, the more join and contribute. If there are forums, Facebook groups, blogs or other places online where the issue is being discussed, then get involved, contribute, and invite people to your investigation. If those places don't exist, then create them yourself: blog about the issue and link to anyone else who's talking about the similar things. All of this will make it easier for people to find out about the investigation when they search for the issue. The ‘How organised was the Jan Moir campaign’ investigation, for example, draws on people who discussed the issue on forums, Facebook groups and Twitter, leading to invaluable insights. Don't forget about physical meetings as well – meeting people is the best way to make strong connections and trust that will help with an investigation.

5. Expertise – having someone who knows their stuff in an investigation can really help, particularly when it comes to identifying particular people, organisations, reports and regulations that are relevant. The investigation ‘Where can I find all of a judge’s rulings?’ is one good example, benefiting from the expertise of journalist Louise Bolotin. Even if you don't know an expert in an area, inviting people who might is a useful tactic. This post provides some useful tips on finding people with specialist knowledge.