"Yahoo has unfortunately been battered in the last year, and (this) caused it to look internally and be protective, and that's nonsense for such a great company and such a great franchise," Bartz said. The company should now "get outward-looking and kick some butt," she said.

The Yahoo board approached her about the job in December, Bartz said, and she was excited to jump in.

"I wouldn't have taken the job if I didn't believe there's a huge opportunity here," she said. "I just see this company as a company with enormous assets that, frankly, could use a little management."

Roy Bostock, chairman of Yahoo's board, thanked Yang as well as outgoing President Sue Decker, saying Decker would help to make a smooth transition and Yang would remain "actively involved" with the company. Bartz said she expected to take advantage of Yang's insights. "No one knows more about Yahoo than Jerry," she said.

Bartz may have more to say about the company's direction when she speaks on Yahoo's conference call on its fourth-quarter financial results, set to be announced Jan. 27.