I think the author explains with great accuracy with how the calling out of "witches" happens. The girls were bored. They were seeking attention and they got it from the magistrates. The girls were trying to "escape [life in Salem]'s suffocating effects (Rinaldi 73). Finally they were given some power in their dull little worlds. "No one our age ever got such attention before" (Rinaldi 97). Boy, did they use it!The description of Ann Putnam, Jr. is so vivid. She truly believes she's "doing this town a favor" by naming the troublemakers and outcasts as witches (88). She tells Susanna that the girls are "doing the Lord's work" by accusing witches (Rinaldi 153). Susanna realizes that Ann actually believes the fits and afflictions are real.
The irony of the entire situation is, of course, that the magistrates did not see the false testimonies the girls gave. The townspeople thought, "Let this matter be dealt with by learned men" (Rinaldi 111). These "learned" men convicted and hanged 19 people and had one man pressed to death.