The Church Growth Research Programme in the UK is doing cutting edge into...well you can guess from the name of the project. It's quite good.
From Anecdote to Evidence: Findings from the Church Growth Research Programme 2011-2013 is the name of the report on everyone's lips and it'll be the subject of much discussion at our Diocesan Synod starting on Friday the 11th of July.
If you want an online copy, you can find it here...