Watch CBS’s analysis.

As they watched the debate, panel members turned a dial between 0 and 100 to indicate their reactions to the candidates’ discussion. 100 indicates a “very positive” response, 0 corresponds with a “very negative” response, and 50 is neutral. Nielsen calculated the average of the 44 respondents’ responses. The panel, and its results, are not part of CBS’s election polling, and the panel is not large enough to be statistically significant according to Nielsen’s standards.

The panel’s overall most positive response came during Biden’s discussion of ending the war in Iraq, at roughly 42 minutes into the debate.  The least positive responses of the night came just moments later, during Sarah Palin’s comments on Iraq.

Palin’s high point came early in the debate (5:00), when she discussed the economic bail-out bill approved by the U.S. Senate and House of Representatives last week.  Her call for better cooperation between Democrats and Republicans (88:52) also triggered some of her most positive responses.

Biden’s lowest response came during his discussion of same-sex benefits at approximately 36 minutes into the debate.

Respondents of all ages showed largely similar responses to the candidates’ comments.  However, panelists aged 55-99 occasionally deviated from the norm, registering more positive responses than panelists between the ages of 18-34 and 35-54 when Biden discussed the policies he would enforce if called upon to fill in as president (approximately 68:12), Dick Cheney’s role as vice president (approximately 77:00), and nuclear weapons control (approximately 59:00).

Panelists aged 18-34 responded more positively than older panelists when Palin offered her take on same-sex marriage benefits (approximately 37:12) and discussed Iraq exit strategies (39:16).

The 22 men and 22 women on the panel had largely similar responses to the debate.

Panelist responses were measured at CBS’s TV City research facility in Las Vegas, using Nielsen technology.

View complete data from CBS and Nielsen’s first debate response panel.

Read coverage of Nielsen’s findings in The Boston Globe and Media General.

On average, 41% of all homes watched the V.P. debate last Thursday — up one-third from the first presidential debate the previous Friday night, which reached an average of 31% of all households.

Of all households, 39% watched neither debate, while 30.3% tuned in to both.  11.2% of all homes tuned in to the presidential debate only, and 19.5% tuned in to just the V.P. debate. 

Both debates drew audiences made up mostly of white viewers with higher levels of income ($100,000+) and education (4+ years of college).

Older viewers (age 55+) made up the largest portion of the TV audiences for both debates (42% – 46%).  However, the Biden-Palin V.P. debate (median age: 52) drew a slightly larger portion of younger viewers than the first Obama-McCain debate (median age: 54).

Homes headed by African Americans made up a larger portion of the presidential debate audience (14.0%) than the V.P. debate audience (12.3%).  African American homes normally account for 12.2% of all U.S. TV households.

Overall, Hispanic viewers were less likely to watch the debates.  Hispanic households, which account for 11.1%  of all TV households in the U.S., made up just 6.3% to 6.5% of the combined audience for the two debates. 

A closer look at the minute-by-minute ratings for both debates reveals few peaks or drop-offs in household viewing, which remained steady throughout both the telecasts.

Read the full report — and stay tuned during the presidential debates for more Nielsen TV audience analyses.

The Biden-Palin matchup set a new V.P. debate TV audience record, beating the previous high of 56.7 million viewers set by the debate between Rep. Geraldine Ferraro and then-V.P. George H.W. Bush in 1984*. 

Biden and Palin’s debate also surpassed the first presidential debate between Barack Obama and John McCain, which drew an audience of 52.4 million last Friday night.

During the last presidential election in 2004, the vice presidential debate between V.P. Dick Cheney and Sen. John Edwards drew 43.6 million viewers.

Coverage of the Biden-Palin debate was carried live on ABC, CBS, FOX, NBC, Telefutura, Telemundo, BBC-America, CNBC, CNN, FOX News Channel, and MSNBC from approximately 9pm to 10:30pm EST Thursday night.

*The universe of potential TV viewers has grown significantly since 1984.

View the full media alert.

Read coverage of Nielsen’s findings by Reuters, the Los Angeles Times, The Boston Globe, the Washington Post, Al Jazeera, Ad Age, and Mediaweek.

One rating point equals 1% of the total TV audience in a given market.

The Baltimore market had the largest TV audience, with a household rating of 59.1, while the Los Angeles market had the lowest household rating: 34.4.

View ratings for Nielsen’s 55 top local metered markets.

Coverage of the debate between Sarah Palin and Joe Biden aired on NBC, ABC, CBS, FOX, PBS, CNN, Fox News, CSPAN, MSNBC, CNBC, Telemundo, and Telefutura.

National ratings for Thursday night’s debate will be available from Nielsen Friday afternoon.

Read coverage of Nielsen’s findings by the Associated Press and in The Wall Street Journal.

Post-debate coverage on ABC and NBC rounded out the top three, with 9.778 million and 9.777 million average viewers, respectively.

CBS and FOX’s post-debate coverage also made the top ten, drawing almost 8 million and just over 4 million average viewers, respectively.

Overall, CBS won the night with an average audience of almost 11.5 million viewers, while ABC took second place with just over 8.7 million average viewers. NBC and Univision claimed third and fourth places with roughly 7.7 million and 4.3 million average viewers, respectively. The CW and the FOX followed in fifth and sixth places with average audiences of roughly 3.8 million and 3.6 million viewers, respectively.

In contrast, John McCain’s campaign has largely eschewed mobile marketing.  But that may just be the right strategy, according to Nielsen Mobile, which reported Monday that mobile advertising is a more efficient way to reach Democrats, rather than Republicans.

As of the second quarter of 2008, mobile media of all types were slightly more popular among Democrats, who were more likely than their Republican counterparts to use data services on their mobile phones, send text messages, or use mobile Internet, according to Nielsen.

View the full media alert.

Read coverage of Nielsen’s findings in MediaPost, Wireless and Mobile News, and Fierce Mobile Content.

Online Buzz
An analysis by Nielsen of the online discussions around more than 30 speakers at the Democratic and Republican conventions showed Obama leading McCain, followed by Palin and Sen. Hillary Clinton.  Vice-presidential candidate, Sen. Joe Biden, rounded out the top five most buzzworthy politicians.

Online Traffic
Web traffic to BarackObama.com increased 32% during the week of the Democratic National Convention.  During the same period, traffic to McCain’s website increased 242%, perhaps driven by the announcement, late in the week, of Sarah Palin as his running mate.

Still, traffic to Obama’s site outpaced traffic to McCain’s site by a two-to-one ratio in the week ending August 31.

Online Advertising
John McCain’s campaign increased its online advertising in August, with image-based impressions up by 254% month-over-month and sponsored search links up by 43%.

Barack Obama’s campaign placed fewer online ad impressions during the same time period, reducing image-based impressions by 48% and sponsored links by 18%.

View the full media alert.

Read coverage of Nielsen’s findings in TV Week, The Boston Globe, Condé Nast Portfolio, and Silicon Alley Insider.

On September 3, Palin will speak before the Republican National Convention in St. Paul, Minnesota.  While her blog buzz continues to dominate Biden’s, TV ratings for her speech will be analyzed tomorrow against night three viewership of the Democratic National Convention when both Senator Biden and former President Clinton spoke.

Wednesday night’s speeches, which featured Former President Bill Clinton’s endorsement of Senator Obama and Senator Joseph Biden’s acceptance of his party’s nomination for vice president, drew 12.2% of all African American viewers — down slightly from the prevous night when Hillary Clinton addressed the convention (12.7%), but up from day one (12%), when Michelle Obama spoke.

Viewers age 55 and older continue to dominate the DNC’s TV audience, with 18.1% of all Americans in that age group — 12.5 million people — tuning in to Wednesday night’s convention coverage on ABC, CBS, NBC, CNN, FOX News Channel, MSNBC, BET, and TV One.

In comparison to day three of the 2004 convention, which drew almost 18 million viewers, the audience for day three of the 2008 convention was still significantly larger (up by a third to 24 million viewers). 

On Wednesday, August 27, 2008, convention coverage varied by network, with all eight networks noted above airing live coverage from approximately 10pm to 11pm EST.

View the full media alert.

Read coverage of Nielsen’s findings in MarketWatch, The New York Times’ “TV Decoder” blog, and Variety.