To enhance education, it is important to keep track of the students' progress and to use appropriate teaching strategies based on the current state of the students' knowledge. From this viewpoint, the problem of selecting an optimal control of the state of student's knowledge becomes a particular case of the general problem of controlling systems. Control theory has shown that in many situations, the optimal way to control a complex system is through a decentralized control, when, in addition to (and sometimes instead of) a centralized controller, each subsystem itself controls its own interactions with other subsystems. This is how the Internet operates, this is how many biological systems operate. In relation to education, this means that to enhance education, in addition to an instructor teaching students, we also need students teaching and helping each other. On the qualitative level, this conclusion sounds very noncontroversial: collaborative learning is a well-known successful educational technique. On the quantitative level, however, the resulting recommendations become more non-trivial: the recommendation is that students be informed about the level of knowledge of fellow students. At first glance, this may sound like a proposal to go back to the old days when student privacy was not a concern and all the grades were posted. The difference between this old practice and our proposal is both in motivation and in implementation. While the main motivation behind the old system was to encourage a (stimulating) competition, our objective is to encourage collaboration. In terms of implementation, since collaboration cannot be forced, we propose to post the grades only with the students' consent, when the students become convinced that this indeed helps all of them to succeed.