Choose a population that is around you and that interests you (your research topic), and think about what would you like to know about that population. Write down what you want to study from that population (your variables). It is easier to choose the population first and the variables second. And then use the population and variables as key words to search literatures to locate a scope of specific questions. Write down your question using your population and variable. Remember to write a question that is going to be specific, answerable, relevant, and limited to a particular time and place. Avoid why questions.