If the problem is required to extract it until the problem clearly enough to tell what research should be started before trial, so it should be back to answer the problem.
If the problem is still wide Must be isolated until the problem is clear enough to say that. What should be researched What should be tried before after The problem is that
If the problem is still wide, split, until the problem is clear enough to tell what should start what research should try it first. The answer that problem.