Later in this chapter, you will work on determining and adapting to your audience when writing, but with an expository essay, since you are defining or informing your audience on a certain topic, you need to evaluate how much your audience knows about that topic (aside from having general common knowledge). You want to make sure you are giving thorough, comprehensive, and clear explanations on the topic. Never assume the reader knows everything about your topic (even if it is covered in the reader’s field of study). For example, even though some of your instructors may teach criminology, they may have specialized in different areas from the one about which you are writing; they most likely have a strong understanding of the concepts but may not recall all the small details on the topic. If your instructor specialized in crime mapping and data analysis for example, he or she may not have a strong recollection of specific criminological theories related to other areas of study. Providing enough background information without being too detailed is a fine balance, but you always want to ensure you have no gaps in the information, so your reader will not have to guess your intention. 

1/ I'm going to write about Vietnamese Museum of Ethnology,where conserves the image of the ancient life ò Vietnamese in the Stone Age and informations about 54 ethnic group.
2/ The readers are my classmates,my teachers,my parents and my siblings.

3/I'm going to write 3 paragraphs : Introduction(Mở), Findings(Thân)and Conclusions(Kết)
4/I'm going to include its name,locations,conserved stuffs,informations about 54 ethnic groups and my thoughts of it