Jennifer’s situation shows that there really is such a thing as studying too much. Her mistake was in trying to master all of the course material. Whether you take one or more than one class, it’s simply impossible to retain every single particle of information you encounter in a textbook or lecture. And, instructors don’t generally give open-book exams or allow their students to preview the quizzes or tests ahead of time. So, how can you decide what to study and “know what to know”? The answer is to prioritize what you’re trying to learn and memorize, rather than trying to tackle all of it. Below are some strategies to help you do this.

• Think about concepts rather than facts: From time to time, you’ll need to memorize cold, hard facts—like a list of math equations or a vocabulary list in a Spanish class. Most of the time, though, instructors will care much more that you are learning about the key concepts in a subject or course—i.e., how photosynthesis works, how to write a thesis statement, the causes of the French Revolution, and so on. For example, Jennifer might have been more successful with her studying—and felt better about it—if she had focused on the important historical developments (the “big ideas”) discussed in class, as opposed to trying to memorize a long list of dates and facts.
• Take cues from your instructor: Pay attention to what your instructor writes on the board or includes in study guides and handouts. Although these may be short—just a list of words and phrases, say—they are likely core concepts that you’ll want to focus on. Also, instructors tend to refer to important concepts repeatedly during class, and they may even tell you what’s important to know before an exam or other assessment.
• Look for key terms: Textbooks will often put key terms in bold or italics. These terms and their definitions are usually important and can help you remember larger concepts.
• Use summaries: Textbooks often have summaries or study guides at the end of each chapter. These summaries are a good way to check in and see whether you grasp the main elements of the reading. If no summary is available, try to write your own—you’ll learn much more by writing about what you read than by reading alone.