When You are Helping to Define a Project Deliverable
Friday, I brought to the class a real-life situation in which a sponsor (the company CEO) vaguely knew what he wanted created, but needed help to fully define the deliverable of the project. We worked together to find ways to define the deliverable - what the sponsor was asking of the Project Manager - by asking questions about what he actually wanted to accomplish with the project. Once we understood this, we were ready to recommend a project that would actually deliver the intended result.
Here is a document that can serve as a guide in such discssions. Note that it aligns with PMI's recommendation (which is on the homepage of this site) regarding how today's PM is not only expert in the tools they use to manage projects - they are also strategic partners with sponsors.