Even the most accomplished writers acknowledge that production of a “finished” text is seldom realized through a simple, linear progression from introduction to conclusion. Rather, accomplished writers understand that writing is a recursive process that requires back and forth movement between various subprocesses (e.g., generating ideas, researching, formulating a thesis, drafting text, revising, editing) constituting the larger process of composing. For example, when you begin research for a paper, you are attempting to answer a research question. Researched writing is just that: a quest.
Even after conducting some research in the library or on-line, you may not arrive at a thesis until you have written several paragraphs—or even pages—of your essay. At that point, you might decide that you need to conduct further research. Surely, you will have to go back and revisit your introductory paragraphs, reconsidering what you have written up until that point in light of your new focus. Within this recursive movement, then, revision often involves refocusing and expanding ideas, rearranging the order of paragraphs, deleting sections of text, as well as refining sentences for clarity and fixing grammatical mistakes.
To support this complex view of writing, your instructors typically will ask you to prepare multiple drafts of the papers they assign so that you can benefit from their feedback (and that of your peers) before those papers are considered “final products” for evaluation. In some cases, these products will not be graded until the very end of the semester in what is commonly referred to as a “portfolio”—a collection of your best works in the best form you’ve been able to muster in a given time frame.