WASHINGTON — HuffPost Pollster is pleased to announce a small but significant change to our polling charts that should greatly reduce the tendency of our most closely watched charts to give undue weight to a few prominent daily tracking polls.
Our polling charts, like the one shown below that plots national Obama vs. Romney vote preference, are not based on simple averages of recent polls but instead use a statistical technique known as local regression (or loess) to plot summary trend lines based on all of the available survey data. We typically refer to the numbers represented by the end-points of the trend lines as polling “trend estimates.”
via HuffPost Pollster Charts: Introducing Weekly Averaging For Daily Tracking Polls.
