So what do Americans think about the announcement of Paul Ryan as the Republican vice presidential nominee?

According to a poll conducted the day after presumptive GOP presidential nominee Mitt Romney named the House Budget chairman as his running mate, Americans may not be all that impressed. But another new survey indicates that Ryan's favorable rating has jumped.

A USA Today/Gallup poll conducted Sunday and released Monday indicates that 39 percent of the public sees Romney's choice of Ryan as excellent or pretty good, with 42 percent saying it's a fair or poor pick, and nearly one in five not having an opinion.

By comparison, 46 percent of registered voters, a slightly smaller pool, said that Sarah Palin was an excellent or pretty good choice immediately after Sen. John McCain of Arizona named the Alaska governor as the 2008 GOP vice presidential nominee. Thirty-seven percent said she was a fair or poor choice and 17 percent had no opinion.

Forty-seven percent of registered voters said Sen. Joe Biden of Delaware was an excellent or pretty good choice immediately after Sen. Barack Obama of Illinois named Biden as his running mate four years ago. One in three said Biden was a fair or poor choice and 20 percent had no opinion.

According to the new survey, nearly half those questioned said Ryan was qualified to serve as president if something happened to Romney, with just under three in 10 saying the seven-term congressman from Wisconsin was not qualified.

Will the Ryan pick change minds?

The poll indicates that 17 percent say having Ryan on the Republican ticket makes them more likely to vote for Romney, with 12 percent saying it makes them less likely to cast a ballot for the presumptive GOP nominee. But two-thirds say the naming of Ryan as Romney's running mate has no effect on their vote.

As expected, Ryan's addition to the GOP ticket is boosting Americans knowledge of the congressman, according to a new ABC News/Washington Post poll also released Monday. Forty-five percent of those questioned in the survey Wednesday through Friday expressed no opinion of Ryan, but that dropped 15 points to 30 percent for those questioned on Saturday and Sunday, after Ryan was unveiled as the Romney's running mate.

And Ryan's favorable rating jumped an equal 15 points, from 23 percent on Wednesday through Friday, to 38% on Saturday and Sunday. And among independent voters, the poll indicates that Ryan's favorable rating jumped 20 points, from 19 percent Wednesday through Friday, to 39 percent over the weekend.

The ABC News/Washington Post poll was conducted Wednesday through Sunday (Aug. 8-12), with 1,189 adults nationwide questioned by telephone. The survey's sampling error is plus or minus 3.5 percentage points.

The USA Today/Gallup was conducted Sunday (Aug. 12), with 1,006 adults nationwide questioned by telephone. The survey's overall sampling error is plus or minus 4 percentage points.