Their responses suggest there is a gulf in voter perception of the candidates' efforts, with Obama widely seen as running the more positive advertising campaign.
Half of those surveyed say Obama's ads are primarily focused on what the candidate stands for, while thirty percent say they have been mostly concerned with attacking his Republican rival. Fifteen percent say both.
The perception is far more negative for McCain: Just 21 percent say the Arizona senator's ads are primarily focused on what he stands for, while the majority – 64 percent – say the ads have been largely concerned with attacking Obama. Twelve percent cite both.
We'll be making further results from the poll available at 6:30 this evening, so check back with CBSNews.com and watch the Evening News for a full report.