Willow Creek Community Church did an extensive survey of their congregation and 30 other congregations (about 20,000 people interviewed) to see how they (or the church they were surveying) are doing in helping people move toward greater intimacy with Jesus Christ. They found much of what they were doing wasn’t helping.
You can watch a video with Willow’s Executive Pastor, Greg Hawkins, here. I appreciate the transparency that he shows in this video.
You can go to the "Reveal" website to learn more as they desire to study more congregations. They want to completely look at how they "do church" with a clean slate with findings that are backed with research and in ways that are rooted in Scripture.