What Are Those Squiggly Lines on CNN Telling You?

What Are Those Squiggly Lines on CNN Telling You?

Viewers of the presidential debates on CNN have a novel feature on their screen -- a box at the bottom showing the real-time reactions of a focus group of undecided voters. Should we take it seriously?

The American Prospect
Sam Boyd | October 15, 2008 | web only

Viewers of the presidential and vice-presidential debates on CNN this year have a novel feature on their screen -- a box at the bottom showing the real-time reactions of a focus group of undecided voters. The results are undeniably bewitching, even for those who don't believe them. "I knew it was completely unreliable and irrelevant," wrote screenwriter Nora Ephron at Huffington Post, "and yet my heart sank and rose according to it."

The visual is the product of a focus-group technique known as dial-testing. Dial-testing relies on hand-held dials that can be turned to register positive and negative reactions in real time. Participants in the focus group -- 30 is a typical size -- sit together and are instructed to continually adjust the dial to reflect how they react to a word, phrase, or sentence.

CNN has seized on the visual power of dial-testing data -- the positions of each dial are aggregated and the resulting numbers are plotted as a line on a graph with the vertical axis representing how positive people feel and the horizontal line representing the time -- as a way to modernize the look of its debate coverage. "If you look at all my colleagues' coverage of the debate, it looks like it could have been done 25 years ago," explains CNN election-coverage producer David Bohrman, who made the decision to broadcast dial-testing results during the debate.

But, besides goosing CNN's ratings, what exactly is the point of broadcasting dial-testing results during a debate? (Both Fox and MSNBC use dial-testing groups for post-debate analysis but do not put the results on screen during the debate.) Skeptics of the network's use of dial-testing point to uncertainty over the meaning of the results, problems with the composition of focus groups, and the distorting effect of watching the debate with a dial in hand. CNN counters that displaying the results keeps viewers engaged and gives them a baseline against which to measure their reactions.