The journalistic conventions of objectivity, depersonalisation and balance, tend to transform the news into a series of quotes and comments from a remarkably small number of sources. Balance means ensuring that statements by those challenging the establishment are balanced with statements by those whom they are criticising, though not necessarily the other way round.
For example, despite claims of anti-nuclear media bias by the nuclear industry, a FAIR (Fairness and Acccuracy in Reporting) study of news clippings collected by the Nuclear Regulatory Commission over a five month period found that no news articles cited anti-nuclear views without also citing a pro-nuclear response whereas 27% of articles cited only pro-nuclear views. (It also found that 72% of editorials and 56% of opinion columns were pro-nuclear.)
Balance means getting opinions from both sides (where the journalist recognises two sides) but not necessarily covering the spectrum of opinion. More radical opinions are generally left out. The US EPA is sometimes used as an environmental source in one story and as an anti-environmentalist source in another. Nor are opposing opinions always treated equally in terms of space, positioning and framing.
Balance does not guarantee neutrality even when sources are treated fairly, since the choice of balancing sources can be distorted. FAIR gives the example of a Nightline show where radio talk show host Rush Limbaugh argued that volcanoes are the major cause of ozone depletion. (This is an example of a growing talk show tradition of “featuring right-wing ideologues as experts on scientific questions.”) Limbaugh was ‘balanced’ with then Senator Al Gore “who argued that the answer to ecological problems was more ‘capitalism’.”
“In practice objectivity means journalists have to interview legitimate elites on all major sides of a dispute” and this gives the powerful guaranteed access to the media no matter how flimsy their argument or how transparently self-interested. But giving equal treatment to two sides of an argument can often provide a misleading impression. Paul Rauber gives an example, in the environmental magazine, Sierra:
Hundreds, maybe thousands of people gather to call for the factory to stop polluting or for the clearcutting to end. In one little corner, half a dozen loggers or millworkers hold a counter-demonstration on company time. That night on the evening news, both sides get equal coverage.
In their attempts to be balanced on a scientific story, journalists may use any opposing view “no matter how little credence it may get from the larger scientific community.” However, according to Boyce Rensberger, director of MIT's Center for Science Journalism: "Balanced coverage of science does not mean giving equal weight to both sides of an argument. It means apportioning weight according to the balance of evidence." (see Reporting on Global Warming)
The journalistic tendency to balance stories with two opposing views also leads to a tendency to “build stories around a confrontation between protagonists and antagonists.”
The expectation of balance seems to be non-existent on talk back radio shows and many cable television channels in the US: "cable news outlets have begun to appeal to particular segments of the audience with targeted political messages... For example, the Project for Excellence in Journalism (2005) found that 52 percent of stories on CNN, MSNBC, and Fox News offered only a single point of view on controversial issues, compared to 20 percent of stories on the national network evening news."