They may allow ownership in that students can help devise parts of problems or their own problems. If students are allowed to create and construct their own problems, again, this would allow them ownership in the process and may help them go beyond problem-solving to problem finding. Grading is more subjective. However, this can be done in an objective manner. Students may be required to judge their own work through some sort of self-evaluation process.
Peers can evaluate peers.
Members of the community may also become involved in the evaluation processes. These may be combined with teacher evaluations, thus creating multidimensional forms of evaluation. Problems may be used in either way or by combining both ways. The money is to be used for a trail that is both aesthetic and also one that can be used for environmental study. Create a design for the trail.