Appreciative Inquiry is a communication theory and tool that focuses on identifying what is working well within an organization rather than focusing on problems. It involves exploring the best experiences and strengths through open-ended questioning to discover the organization's core values and shared visions for the future. Appreciative Inquiry was developed in the 1980s and uses a 4D model of Discovery, Dream, Design, and Destiny to help organizations evolve by building on past successes.