One major purpose of the thesis is to predict what will follow. It does this for both writer and reader. It provides the writer with purpose and direction throughout the composing process. For the reader it creates expectations about the form and content of what's to come, and the reader's satisfaction with the final essay will depend largely upon whether these expectations have been satisfied.
Still, while we want the thesis to set up expectations for the total paper, few of us are prophets. Because we don't know what we want to say until we discover it by writing, the original thesis is often only a hunch or hypothesis about where the paper will go. It isn't unusual for the sentence that started the paper growing to make a commitment the paper doesn't fully honor.
While writing, you may have grown to a new awareness of your subject, so that your original thesis now seems imprecise or misleading. While writing, you may have grown to a new awareness of your subject, so that your original thesis now seems imprecise or misleading. If so, you need to re-state your thesis to take your new understanding into account.
Your revised thesis becomes a distillation of your entire paper, and because by now you've seen not just the general outline, but the main divisions and even the supporting details, you may want to include some of this in your thesis. For instance, "The major responsibility for preventing dental problems lies within you," might be revised as follows: "Learning a few basic skills and practicing them in a daily routine will help keep your dental problems to a minimum." The second thesis not only states the main idea more precisely but also forecasts the paper's main divisions and the order of discussion.
If you can write a single sentence that clearly indicates the relationship between the various parts of your paper, those parts probably fit together well. Seeing this, your reader will perceive your paper to be clear, unified, and well-organized.
6.16 Look back at one of the papers you have been working on to see if you can revise the thesis to more accurately reflect your paper's content and structure.