The frequentist answer of 1⁄3 is effectively making the implicit assumption that the parent would have said “at least one boy” either if both were boys or if there were one of each, and “at least one girl” if both were girls. Eliezer2008′s 1⁄2 answer effectively assumes that the parent would have said “at least one boy” if both were boys, “at least one girl” if both were girls, and either with equal probability if there were one of each. “No alternative” assumes the parent is constrained to (truthfully) say either “at least one boy” or “at least one girl”, an assumption that strikes me as being bizzare.
Will Pearson, you could not be more wrong. Winning money at games of chance is precisely what probability theory was designed for.
Cat Dancer,
The frequentist answer of 1⁄3 is effectively making the implicit assumption that the parent would have said “at least one boy” either if both were boys or if there were one of each, and “at least one girl” if both were girls. Eliezer2008′s 1⁄2 answer effectively assumes that the parent would have said “at least one boy” if both were boys, “at least one girl” if both were girls, and either with equal probability if there were one of each. “No alternative” assumes the parent is constrained to (truthfully) say either “at least one boy” or “at least one girl”, an assumption that strikes me as being bizzare.
Will Pearson, you could not be more wrong. Winning money at games of chance is precisely what probability theory was designed for.