Student as a Tutorial Designer

As an educator, can you name some specific types of lessons or topics that would be particularly well suited for student tutorials?

I feel that any lessons could be turned into lessons for student tutorials.  Especially math lessons. Some that stand out in other subjects would be Ecosystems in science or figurative language in English. 

How does the work of student tutorial designers fit within Daniel Pink's analysis of PURPOSE as a key motivator of high-quality student work?

Student tutorials designers best fit Pink's analysis of purpose because it allows students to teach and be the teacher.  This will help students be engaged and want to learn and help in the classroom. 

Beyond the benefits for students who use the tutorials, can you identify educational benefits for students who do the work of tutorial design?

Some educational benefits for students would be having or showing different learning styles. Also being able to work altogether as a team. It can help students be open minded and interact with one another.