As you read the assignment, think about what the teacher does in class. Social science classes often expect more research. Humanities classes thrive on interpretation and analysis. Instructors spend time designing courses, sometimes even arguing with their peers about the most effective course materials. Figuring out the overall design to the course will help you understand what each assignment is meant to achieve.
Most undergraduates think of their audience as the instructor.
True, your instructor is a good person to keep in mind as you write. Remember, even if the instructor knows everything there is to know about your paper topic, he or she still has to read your paper and assess your understanding. In other words, teach the material to your reader. The level of information you use depends on who you think your audience is. If you imagine your audience as your instructor and she already knows everything you have to say, you may find yourself leaving out key information that can cause your argument to be unconvincing and illogical.