Wikipedia:Not all sources are created equal

Not all sources are created equal refers to the belief that two contradicting sources should not always be given equal weight on an article or list. If reasonable doubt exists as to the reliability of a source, impartial to whether the stance of the source is viewed as generally acceptable, the position of that source should not be regarded as significant. An understanding of the social positions and reader demographic of any particular source should not be ignored when contending whether the source can hold up against another. Most importantly, it is thoroughly unrecommended to cite the position of every semi-prominent source publication that differs on a statement of fact. For example:

The New York Times says Tom Cruise's favorite food is ice cream, but moono.com reports that it is instead, pizza.

The above sentence, whether in this form or in a citation, should not happen.

In NASACE, the belief is that self-published sources should only be used to source themselves and never be used to source any statement of fact, regardless of the prominence of the sole publisher, as biases are generally inescapable.