Appreciative Inquiry's (AI) biggest contribution to the field initially was to take a positive approach. It is based on the idea that we find what we are looking for. So if we always look to solve problems, we will always find problems. If we look for the strengths in what we already know how to do (or the life blood of the organization) we will find the areas on which we can build.
AI was originally an approach to action research based inpart on the belief that we find what we set out to look for. Thus the focus on the appreciative approach. As research designed to create change, after gathering data about what is working well, the group works together to envision what could be and to begin to take steps to create that future. The action steps grow out of the energy of the group -- if no one is inspired to take on one part of the anticipated work, then that part is set aside. If there isn't energy for it in the group then it is not important now. This is a very organic process that develops out of the group's enthusiasm with process guidance from the leaders.
http://www.appreciative-inquiry.org/AI-Life.htm This link describes the history of the development of AI in the late 80's. David Cooperrider has not tried to hold onto AI -- one doesn't have to be certified in it. He encourages people in his workshops to go forth and try it and continue to research how it works best. So the links I gave you to AI projects displayed the parts of AI that different leaders had picked up and found useful.