Whether it's related to census data, budget deficits or sports stats, reporting on numbers can be a complex endeavor.
A group of experts on the issue at BBC, including business editor Robert Peston, economics editor Stephanie Flanders and home editor Mark Easton, compiled a list on BBC's journalism blog of the most common errors journalists make when dealing with figures.
Here are a few:
Journalists often report numbers that seem astronomical without providing additional context, the authors say. When politicians discuss fund allocation, for example, monetary amounts that reach the million and billion marks should be evaluated against the size of the task. Although the £300 million (US$470 million) promised by former United Kingdom Prime Minister Tony Blair to create free childcare may sound high, the article points out that it actually comes down to £1.15 (US$1.81) per child per week. "So, while it was reported as a large sum, it was actually very small from the point of view of what it was intended to achieve," BBC experts say.
Report "shock figures"
Too often journalists are seduced by the shock value of extreme numbers without doing sufficient research. A seemingly newsworthy amount can signal a problem with its accuracy or a misinterpretation of its meaning.
Focus on outliers instead of averages
When reporting data, it's important to avoid exceptional numbers within the set that don't accurately represent the overall findings. For example, the article mentions a news story with the headline "Global warming could raise temperatures by 11 degrees Celsius," in which a climate prediction model was referenced. But the model only produced the 11-degree figure one out of 2,000 times that it was run--making the headline deceptive to readers.
Report fluctuation without explanation
Plenty of news stories mention a rise or fall in numbers, but often part of the back story is missing. "They are a news staple: a risk doubles if you use a mobile phone, stop-and-search increases four-fold, breast cancer rates go up with drinking, for example," it says. "They’re staples, but often with a depressing omission: any useful information whatsoever." It's important include both the cause of the change and the number's starting point, the authors say.