Two weeks ago, People magazine was granted an exclusive interview with Senator John McCain’s new running mate, Gov. Sarah Palin of Alaska, who spoke about motherhood and career, life in Alaska and the historic nature of her candidacy.

She has not given an interview since, eschewing the traditional television news circuit traveled by a vice-presidential nominee.

Ms. Palin will break that news media blackout on Thursday, when she will begin two days of interviews by the ABC News anchor Charles Gibson.

The sessions could be the first test of Ms. Palin’s ability to parry substantive questions on foreign and domestic policy, and as she flew back to Alaska on Wednesday, she brought with her a squad of Mr. McCain’s top policy advisers to help her prepare. In a broader sense, the interviews will also provide fresh material for what is now an intense war between the campaigns to define Ms. Palin in the public mind, a battle that both campaigns consider potentially critical to the election outcome.