Dr. Siebert is the president of the California Institute of Technology and is therefore the boss of pretty much every person on the show except Penny. Nevertheless, he ends up being treated very poorly by many of them, often inadvertently. Sheldon Cooper shows up at his house in the middle of the night and Siebert walks into a prank intended for Sheldon's rival Barry Kripke.Background: He is married and has a teenage daughter.