I've read a very interesting article about the currency exchange in a classroom. Most students offer teachers attention, curiosity and participation in return for their efforts. In exchange for their efforts teachers offer students approval, praise and positive attention. It is important to recognize that the currencies we value might differ from he ones our students value.
There are however currencies that is problematic, e.g. sarcasm. Some students might use it as a way of getting respect from their peers as it shows they are lever and funny. If students feel that teachers don't value or understand their currencies, they often assume that there is no place for them in the classroom.
Teachers often attempt to address classroom problems by attempting to connect with students through their interests or with rewards. Getting to really know 20-30 students in a short period of time and make a personal connection with each one is also seldom possible. A possible alternative would be to work out what currencies they value and plan your strategies around that.
How might this look in practice? If you have a group of students who value the approval of friends more than good scores, trying to get them to place greater value on scores might not be the best strategy. A much better way might be to develop a class culture where students push one another to do their very best - in short: use the currency they value.
(Robyn R Jackson: Start where your students are)