NEW YORK – When Kara DioGuardi accepted her job as the fourth judge on “American Idol,” she did not immediately grasp the enormity of a full-time gig on the most-watched TV show in the nation.

“I probably in my own way didn’t really take in what a huge thing it was, just `cause it would be so overwhelming,” she said. “Until I kind of showed up and was like, `Omigod, what am I doing here? This is, like, huge!’ And then it really hit me when we went live that, wow, `I got to speak live in front of 30 million people?’”

Since joining the judges’ panel, DioGuardi has weathered the curve balls of live television, eye rolls from Simon Cowell and criticism of her judging abilities by the viewer peanut gallery. As the eighth season progresses to a showdown between Adam Lambert and Someone Else, the 38-year-old songwriter and producer’s “saving grace” has been connecting with the finalists and helping steer them in the right direction, by way of her industry expertise.

“It’s not an easy job,” DioGuardi said in an interview from Los Angeles. “I mean, there was nothing wrong with that panel. It wasn’t like I had to fix something. It was great. So to come in and kind of be part of it was really tricky. …