What information does katherine hope to gain by tying biancas hands and questioning her?

In "The Taming of the Shrew", Katherine chases Bianca, insulting her furiously. Later, she ties Bianca's hands and questions her, but she refuses to answer, so she tries to beat her, hoping to gain information on which of the suitors Bianca prefers. Baptista, however, breaks the fight with his arrival.