If you’re like me (which, of course, you don’t really want to be), you would find it fun in a way to explore the disparity between a new CBS Poll and the latest Gallup Daily Tracking Poll on the question of President Obama’s job-approval rating.
The difference is not all that dramatic when you consider that both polls have a stated margin of error of plus or minus three percentage points.
What strikes me, however, is that CBS represents its numbers as an indication of a downward trend in Obama’s approval rating, while Gallup sees an upward trend.
One possible explanation of this dichotomy is that CBS is comparing its latest figures with those from a poll of a month ago, while Gallup is showing a trend in a three-day rolling average.
Gallup conducts its poll every day, and each day it reports a three-day rolling average. Yesterday’s report on Obama’s approval rating showed an increase of two percentage points over the previous day’s report.
Putting it another way, Gallup sees an upward trend in just the past few days, while CBS sees a downward trend in a month-to-month comparison.
The CBS poll was conducted last Wednesday through Sunday. Gallup’s three-day rolling average covers polling conducted Friday through Sunday.
(NOTE: If you click on the link to the Gallup poll after Noon (CDT) today, you’ll likely get updated results, which well may differ from those cited in this post.)