From The Art and Popular Culture Encyclopedia
False balance is a real or perceived media bias in which journalists present an issue as being more balanced between opposing viewpoints than the evidence actually supports. Journalists may present evidence and arguments out of proportion to the actual evidence for each side, or may omit information that would establish one side's claims as baseless.
An example is "objective coverage" of lynching in the 1890s by US journalists, which failed "to recognize a truth, that African-Americans were being terrorized across the nation." False balance is often found in political reports, company press releases, and information from entities with special interests in promoting their respective agendas.
Other examples of false balance in reporting on science issues include the topics of man-made vs. natural climate change, the relation between thimerosal and autism and evolution vs. intelligent design. For instance, although the scientific community attributes global warming to the effects of the industrial revolution, Giving equal voice to scientists on both sides makes it seem like there is a serious disagreement within the scientific community, when in fact there is an overwhelming scientific consensus favoring anthropogenic global warming.
False balance can sometimes originate from similar motives as sensationalism, where producers and editors may feel that a story portrayed as a contentious debate will be more commercially successful than a more accurate account of the issue. However, unlike most other media biases, false balance may actually stem from an attempt to avoid bias; producers and editors may confuse treating competing views fairly—i.e., in proportion to their actual merits and significance—with treating them equally, giving them equal time to present their views even when those views may be known beforehand to be based on false information.