JOT emerged while looking for materials and techniques to help teach Java. Although textbooks are essential, even the best of them tend to help you expand your knowledge and understanding only after getting over the initial hurdle of learning to program. Online reference materials similarly help people who are already reasonable programmers to find what they need. Experience with lectures and lab supervision has shown that although everyone needs occasional personal tuition when they get stuck, it is easy to get addicted to asking for help, and it is really important to learn to solve your problems for yourself.