Researched information can never be biased
No, that isn't true at all. People research and find only information that supports their own position all the time. It is true that using research helps you to get accurate information rather than just guessing... but in order to have an unbiased result, the person doing the research has to be unbiased, and actually read all of the perspectives, and no matter which one he or she agrees with, present them all accurately along with any conclusions.
Such information has never been researched or studied.
Of course. If your researching, let's say, the Affordable Care Act and you only interview Republicans, you're going to get only a one sided view of the program.
Biased
yes
Biased rumor - never substantiated
Propaganda is certainly biased (and tries to actively convert people to the propaganda writer's biased view). Manifests may on occasion be seen by some as biased information - think only of the Communist Manifest - but normally has the meaning of "information to make something clear". If one correct answer is required, choose propaganda.
Primary sources should never include biased or subjective interpretations, speculations, or opinions. They should only include factual information, data, or firsthand accounts of events.
Biased
People researched because to get the information they are looking for.
Biased
Biased