NewsBeat

September 2022 NewsBeat 17 want to examine the relationship between orange juice consumption, measured in ounces, and flu vaccination rates, measured as the number of vaccines administered each month per 100,000 U.S. residents. The process of standardizing data in- cludes dividing each numerical data point by the standard deviation of the dataset. Doing this changes the units of measure- ment. Instead of expressing findings using common units such as ounces, inches and pounds, they must be reported in terms of standard deviations. Hypothetically, scientists looking at or- ange juice consumption and flu vaccination rates could conclude that a one standard deviation increase in juice consumption is associated with a one standard deviation reduction in vaccination rates. While standardizing datasets can make them easier for researchers to work with, Brian Healy, an associate professor of neurology at Harvard Medical School, notes many people might have difficulty under- standing the results. He urges journalists to read these papers closely. "The problem is, unless you look really closely in the paper, you'll have no idea what a one standard deviation means," says Healy, who's also the lead biostatistician for the Partners Multiple Sclerosis Center at Brigham and Women's Hospital in Boston. "Do understand the units that results are being shown in," he adds. "If there is a number reported, you want to make sure you understand how to interpret the number and you can't understand how to interpret the number without knowing the units." 4. Scientists can use standard deviation to help them confirm whether a data point they consider an outlier actually is an outlier. Outliers are extremely high or low values that can complicate statistical analyses and skew results. Many researchers will remove or alter outliers caused by error — for example, an error in collecting or entering data. When you look at a graph of all the data in a dataset, some data points appear to be outliers because they differ so much from the others. Since the standard deviation of a dataset takes into account how far away individual values are from the average, scientists often use it to gauge whether an unusual data point is an outlier. This meth- od works well for datasets that follow the pattern of a symmetrical, bell-shaped curve in which the majority of data converge near the center of the bell, where the average value is located. After calculating the standard deviation for that dataset, it's easy to spot outliers. A general rule of thumb for data that follows a bell-shaped curve is that approximate- ly 99.7% of the data will be within three standard deviations of the average. Data outside this boundary are usually deemed outliers. Although the standard deviation of a dataset is affected by outliers, journalists should not assume a large standard devi- ation indicates data quality problems. As Rumsey writes in Statistics for Dummies, "a large standard deviation isn't necessarily a bad thing; it just reflects a large amount of variation in the group that is being stud- ied." This article was reprinted from The Jour- nalist's Resource, which extended thanks to Troy Quast, a professor of health economics at the University of South Florida's Col- lege of Public Health, and Brian Healy, an associate professor of neurology at Harvard Medical School, for their help creating the tip sheet. We Need Your Support! NEW YORK Are editorial cartoons part of your digital content strategy? Sharp, perceptive, unpredictable — editorial cartoons are a great reader engagement tool. NYPA's $5 Editorial Cartoon Exchange provides a low cost library of the latest editorial cartoons on the hottest topics. If you are an editorial cartoonist who would like to earn a little money and a wider audience for your work, email jill@nynewspapers.com If your news organization would like to republish the works of some of the state's best cartoonists, check out NYPA's editorial cartoon exchange at www.nynewspapers.com — click under "QUICK LINKS" to "Editorial Cartoon". Increase reader engagement in print or online by publishing editorial cartoons. A hot cartoon on your editorial page, your home page, or on your Facebook page... "The problem is, unless you look really closely in the paper, you'll have no idea what a one standard deviation means." Brian Healy Neurology professor

• Cover