The difference between persuasive writing and objective writing is actually implied right in the names of these two styles of writing. In persuasive writing, an author hopes to convince an audience of something. Objective writing, on the other hand, presents facts and information organized in an accessible way, without any specific conclusions or hidden agenda. Many wiseGEEK articles are excellent examples of objective writing.
Both of these types of writing have a specific place in the world, and they are both valuable. Many literature classes teach students to identify objective and persuasive writing, and students are often encouraged to refine their skills in both, so that they can be better writers and communicators. There are times when it is necessary to be objective, and times when being persuasive is crucial.
In a piece of persuasive writing, the author's goal is to convince the reader to agree with him or her. Typically, the writing includes a series of arguments, many of which are bolstered with facts which support the author's point of view. Most classically, this style of writing includes an introduction, which acquaints readers with the topic to be discussed, followed by a body, with the meat of the arguments, and a wrap-up conclusion to reiterate the point. Typically, a thesis statement like “the death penalty is cruel and unusual punishment” or “gun control laws do not work” is a tip-off that you are reading persuasive writing.
Objective writing is ideally characterized by the unbiased presentation of facts. Many journalists strive to produce objective writing, providing their readers with the information they need to make their own choices. To use an example from above, objective writing about the death penalty would include a more general discussion of the history of the death penalty, various execution techniques, and perhaps information about research on how humane these techniques are, but the author would make no judgment or persuasive statement about the death penalty.
Both objective and persuasive writing require critical thinking on the part of the author and the reader. The author needs to be able to clearly present information in a format which will be logical to the readers, while the readers need to be prepared to think about the information presented. In both cases, readers should always draw their own conclusions after thinking critically about the information, and in the case of persuasive writing, it is a very good idea to read a piece written by the other side before you make a decision.