Undecided voters were more engaged and attentive during the Republican National Convention (RNC) than during the Democratic National Convention (DNC), according to a media research firm.

Uncommitted voters were most engaged in Sen. John McCainJohn Sidney McCainMcCain rips Trump for attacks on press NSA spying program overcomes key Senate hurdle Meghan McCain says her father regrets opposition to MLK Day MORE's (R-Ariz.) Sept. 4 acceptance speech. The addresses by Sen. Barack ObamaBarack Hussein ObamaMcCarthy: ‘No deadline on DACA’ Democrats will need to explain if they shut government down over illegal immigration Trump’s first year in office was the year of the woman MORE (D-Ill.) and Gov. Sarah Palin (R-Alaska) were the second most engaging programs to uncommitted voters. Nielsen also found that likely voters were 12 percent more attentive to the RNC than to the DNC.

McCain's speech drew a hefty 38.9 million viewers, 500,000 more than the 38.4 million viewers who watched Obama's Invesco Field acceptance speech the week before.

The research was conducted by Nielsen AIG, a firm which studies ads, product placement, and program sponsorship during television programs.

-Michael O'Brien