Making youth participation meaningful AND sustainable--that's the rub, indeed!
A survey could be a useful tool to gather young people's ideas about some of the design and development issues in evaluation. I've mainly seen them used for summative evaluation purposes, but what if such a survey were used in the beginning of an evaluation development process? For example, survey questions that ask young people what they wish people would ask them about the barriers or aids that exist in their own lives to program goals like K-12 retention and access to post-secondary education. A kind of "this is what tends to get measured, but what do you think affects these outcomes?" approach.
On the other hand, it seems that surveys are a go-to tool for gathering youth input, and I know I struggle a bit to make surveys meaningful instruments while also not relying too heavily on them. What about incorporating art, or other creative tools to solicit young people's ideas? Like a survey, this could come either at the beginning or the end of an evaluation process, allowing youth to articulate visually or in other ways their own theories of action about what would help them achieve the goals around which the program is based. (If anyone knows of an example of using art this way in a youth program, I'd love to hear it!)