In the weeks since Steve Jobs unveiled his latest creation, public perception of the iPad has been all over the lot — up, down and sideways.

The chart at right, produced by YouGov’s BrandIndex, is a snapshot of that roller coaster ride taken in the days before and just after Apple (AAPL) aired the first iPad TV ads during the 82nd Academy Awards.

“The Oscar night ad debut gave Apple a short-lived shot in the arm with adults 18+, sending it from a 35 buzz score the day after the Oscars to 38.5 a couple of days afterwards,” says YouGov’s Drew Kerr. “However, perception has been rocky since then, with the brand’s buzz score now at 32.4, reflecting the public’s indecision about the product.”

YouGov determines a brand’s “buzz” by asking 5,000 Americans every day “If you’ve heard anything about the brand in the last two weeks, was it positive or negative?”

Respondents are drawn from an online panel of more than 1.5 million individuals. A score can range from 100 to -100 and is compiled by subtracting negative feedback from positive. A zero score means equal positive and negative feedback. YouGov claims a margin of error of +/- 2%.

See also:

• The second-richest man at the Oscars
• The wild Apple iPad ruckus begins
• iPad pre-orders: 10,000 per day

[Follow Philip Elmer-DeWitt on Twitter @philiped]