I believe that researchers should be objective. If you are researching something, in my experience, you are looking for information which is factual. You cannot change the facts that you find in your research so it would be wasted time to try and be subjective with your research. Unless of course you are research for an argumentative paper, in this case, you could leave out the information which disagreed with the point you are trying to make. Whether or not that would still be being objective or not, I don't know?