What comprises 'evidence'?

There is a strong belief that policy and action, especially in the public sphere, should be underpinned by evidence that supports that policy and / or action.

What sorts of evidence would you find most persuasive here? Academic reseach? Opinion polls? Personal experience? History?

Does this depend on what aspect/s of our experience the policy or action addresses?

Are communities just small societies?

We often think of communities as the locale where we live; but obviously they can be virtual, historical, interest or other sorts of groups too.

So do lots of ‘communities’ put together comprise a full ‘society’?