On this edition of Conversations, Valerie Tripp talks with host Dan Skinner about “Izzy Newton and the S.M.A.R.T. Squad: Newton’s Flaw.” Among her many credits, Valerie Tripp was part of the creative team behind the American Girl series and has written many of the American Girl books. She also wrote American Girl’s “Welliewisher” and “Hopscotch Hill School” books.