Explain an important and interesting concept, one you already know well or are just learning about. Consider what your readers are likely to know and think about the concept, what they are likely to find interesting about the topic, what you might want them to learn about it, and whether you can research it sufficiently in the time you have. Explain an important and interesting concept, one you already know well or are just learning about. Consider what your readers are likely to know and think about the concept, what they are likely to find interesting about the topic, what you might want them to learn about it, and whether you can research it sufficiently in the time you have.