You know about the scientific method. That’s where you take a hypothesis and test it, thereby finding out if you were right or if you can prove it wrong. This concept is so engrained into our culture and thinking that it influences the way our courts work (innocent until proven guilty) and much more (I’m running out of ideas, I’ve been writing too long today—if you get one, e-mail me and I’ll throw it in the next revision).
The second most important idea connected to the scientific method is that of objectivity. If we can remove our feelings and everything subjective (having to do with the person, not those things that are not the person), then we assume that we won’t have any influence on the experiment at hand.
This is why, in formal papers, you have been told over and over again not to say "I" or "I think" or "I feel" or "I believe" (and they're usually right, read the final paragraph for exceptions), and to only include your opinion if you disguise it as well-documented fact.
More recently, however, scientists have begun to realize that it is impossible to remove themselves completely from many experiments. I won’t go into complex (and fascinating) details here, but I will point out that this is not, by any means, the first time that science seems to have disobeyed its own most basic rules. As a matter of fact, if one single discovery has been consistent over time, it is that we are consistently wrong about our most basic assumptions and know next to nothing about ourselves and the universe.
This is no reason to discontinue our efforts to discover truth or to understand what we currently believe, but keeping this in mind just might keep you ready, on your toes, to discover the next breakthrough in science and to win the next Nobel Prize.
Stepping Out of Objectivity:
One reason you might sometimes wisely choose to avoid writing the typically fact-laden, emotion-bare objective paper is that people are not generally
rational. Any objective observer will notice that most people do not tend to make
most important decisions based on fact but on emotions. A writer wanting to operate
most effectively, then, will not risk leaving out appeals to emotion
when appropriate. This may (and should!) be done without sacrificing logic.
It's good to be idealistic and hope that sound reason will have a growing effect on human choices, and it's good to base appropriate decisions (like whether ornot to continue in school, whether or not to brush your teeth, whether or not to drink and drive) on reason and logic, but by all means, order your favorite flavor of ice cream, not the one with one less gram of fat.
And if you include yourself ("I think" etc) in your paper, do it because your opinion matters to your readers--because you are some kind of authority (you have a Ph.D or special experience with the topic) and they know it. Otherwise, obey your teachers' good advice.