Sam Boyd takes a look at the squiggly lines on the bottom of the screen during CNN’s debate broadcasts. It’s called “dial testing” for one thing.
Unfortunately, he doesn’t get at one thing I always wonder — why do the dial as a positive-negative axis rather than an Obama-McCain axis? The way they do it makes it very hard to interpret what’s happening when McCain attacks Obama and the dial goes negative. Does that mean the attack is working or that it’s backfiring? Similarly, we know that dial testers don’t like it when the candidates start fighting, but more interesting is who’s winning the fight. A different dial could give us that information.