- Using "billion" instead of "million," or vice versa.
- Insufficient examination of numbers given by sources.
- Transposing numbers. One way to guard against this is to call any phone numbers reported -- after they've been typed in to the copy.
"Percent" and "percentage points" are not the same. For example, the difference between 4 percent and 7 percent is 3 percentage points, not 3 percent.
- Percentage Calculator, from Maths Helper.
Surveys and polls should be conducted scientifically but often aren't. If the pollsters do not know the margin of sampling error, the poll probably has no scientific validity and its results have little meaning or validity.
When reporting poll results, give readers the information to judge how valid the poll is. At a minimum, this means at least indicating the margin of sampling error, or whether that information is not available.
Poll reporting should also indicate who conducted the poll and who paid for it.
The Associated Press stylebook has an entry on polls.
- External link
- Polls - 20 Questions A Journalist Should Ask About Poll Results, From the National Council on Public Polls.
Journalists tend to be weak in math. Here are some links that can help.
- currency converter, from Oanda. 164 currencies.
- Inflation Calculator, USA, from the Bureau of Labor Statistics.
- Science - Notes from the Science Lab, by the Philadelphia Inquirer. Via ACES.
- test by Phil Meyer, At UNC-Chapel Hill.
- test by Steve Doig, interactive. Doig is from Arizona State University. The test is via Investigative Reporters and Editors.
- Tip sheets
- math tips, By Douglas Starr of Texas A&M University, via ACES.
- math and numbers, by Malcolm Gibson of the University of Kansas. Via ACES. "Quest for Accurate Numbers."
- math and statistics, Robert Niles' Journalism Help. Organized well. Also includes sections about finding data on the Internet and questions to ask political candidates.
- Numbers Game Issues Guide, by Media Channel.
- Web sites
- Glossary of Math Mistakes, by Paul Cox
- John Allen Paulos' site; Paulos' work includes the book "A Mathemetician Reads the Newspaper"
- Stats -- Statistical assessment, at George Mason University
- Also see