I'm working on an agenda for a nonprofit client's daylong session that's bringing together a group of 35 leaders in a particular subject matter area to talk about a very specific, niche aspect of that subject matter area. Some of the attendees have decades of experience with the niche area; others are brand-new to the concept. Success for this client is that by the conclusion of the meeting, we'll have gathered the group's substantive input on how and where stakeholders in this area should invest their time and resources to bring this niche work to larger scale -- and also that we will have generated increased interest and buy-in from the meeting attendees. Any thoughts on specific exercises/formats that will allow us to draw from the wisdom of both the experts AND novices in the room -- and allow everyone to both get and give to this process in meaningful ways -- without overcomplicating the session?