MANY people doubt what they read and hear in the news. In the United States, for example, a 2012 Gallup poll asked people “how much trust and confidence” they had in the accuracy, fairness, and completeness of the news reports of newspapers, TV, and radio. The answer from 6 out of 10 people was either “not very much” or “none at all.” Is such distrust justified?

Many journalists and the organizations they work for have expressed a commitment to producing accurate and informative reports. Yet, there is reason for concern. Consider the following factors:

MEDIA MOGULS. A small but very powerful number of corporations own primary media outlets. Those outlets exert a strong influence on which stories get covered, how they are covered, and how prominently they are covered. Because most corporations are designed for profit, decisions made by media outlets can be motivated by economic interests. Stories that may hamper the profits of the owners of a news organization may go unreported.

GOVERNMENTS. Much of what we learn in the media has to do with the people and the affairs of government. Governments want to convince the public to support their policies and their officials. And because the media draw on content from the government, journalists and government sources at times cooperate with one another.

ADVERTISING. In most lands, media outlets must make money in order to stay in business, and most of it comes from advertising. In the United States, magazines get between 50 and 60 percent of their revenue from advertising, newspapers 80 percent, and commercial television and radio 100 percent. Understandably, advertisers do not want to sponsor programs that cast an unfavorable light on their products or style of management. If they do not like what a news outlet is producing, they can advertise elsewhere. Knowing this, editors may suppress news stories that cast a negative light on sponsors.

DISHONESTY. Not all reporters are honest. Some journalists fabricate stories. A few years ago, for example, a reporter in Japan wanted to document how divers were defacing coral in Okinawa. After not finding any vandalized coral, he defaced some himself and then took photos of it. Photos can also be manipulated to deceive the public. Photograph-altering technology has become more effective, and some manipulations are practically impossible to detect.

SPIN. Even if facts are as solid as bricks, how they are presented depends on the judgment of the journalist. What facts should be included in a story, and which should be left out? A soccer team, for example, may have lost a match by two goals. That is a fact. But why the team lost is a tale that a journalist can tell in many ways.

OMISSION. In arranging facts to create a compelling story, journalists often exclude details that would introduce complications or unresolved issues. This causes some facts to be exaggerated and others to be diminished. Because television anchors and reporters may sometimes need to tell a complex story in a minute or so, important details can be skipped.

COMPETITION. In recent decades, as the number of television stations multiplied, the amount of time viewers spent watching just one station fell drastically. To keep viewers interested, news stations were compelled to offer something unique or entertaining. Commenting on this development, the book Media Bias states: “The [television] news became a running picture show, with images selected to shock or titillate, and stories shortened to match an [ever-shorter] attention span on the part of viewers.”

MISTAKES. Because they are human, journalists make honest mistakes. A misspelled word, a misplaced comma, an error in grammar —these can all distort the meaning of a sentence. Facts may not be carefully checked. Numbers too can easily trip up a journalist who, in the scramble to meet a deadline, might easily type 10,000 instead of 100,000.