Example: Imagine that you want to write a descriptive essay about your grandfather. You've chosen to write about your grandfather's physical appearance and the way that he interacts with people. However, rather than providing a general description of these aspects, you want to convey your admiration for his strength and kindness. This is your reason for writing the descriptive essay. To achieve this, you might focus one of your paragraphs on describing the roughness of his hands, roughness resulting from the labor of his work throughout his life, but you might also describe how he would hold your hands so gently with his rough hands when having a conversation with you or when taking a walk.
Writers tend to read over their own papers pretty quickly, with the knowledge of what they are trying to argue already in their minds. Reading in this way can cause you to skip over gaps in your written argument because the gap-filler is in your head. A problem occurs when your reader falls into these gaps. Your reader wants you to make the necessary connections from one thought or sentence to the next. When you don’t, the reader can become confused or frustrated. Think about when you read something and you struggle to find the most important points or what the writer is trying to say. Isn’t that annoying? Doesn’t it make you want to quit reading and surf the web or call a friend?