Only two of the 10 techniques examined turned out to be really effective - testing yourself and spreading out your revision over time. "Students who can test themselves or try to retrieve material from their memory are going to learn that material better in the long run", says Prof Dunlovsky. "Start by reading the text book then make flash cards of the critical concepts and test yourself. "A century of research has shown that repeated testing works." This is because the student is more engaged and it is harder for the mind to wander.He adds: "Testing itself when you get the correct answers appears to produce a more elaborative memory trace connected with your prior knowledge, so you're building on what you know". Starting lateHowever the best strategy is to plan ahead and not do all your revision on one subject in a block before moving on to the next - a technique called "distributed practice".Prof Dunlovsky says it is the "most powerful" of all the strategies.