 The consequences of minimizing regressive mind changes are different for the question of whether all ravens are black. Consider again the contrary method that asserts that there is a nonblack raven after observing a sample of black ones. As shown in the Table and discussed above, the contrary method has to eventually change its hypothesis after seeing more black ravens to conjecture that all ravens are black, and then, upon observing a white raven, return to its true initial hypothesis that there is a nonblack raven. Thus the contrary method undergoes at least one regressive mind change in the worst case. On the other hand, the generalizing method that asserts that all ravens are black after observing a sample of black ones changes its conjecture only when a nonblack raven is observed---a progressive mind change from a false hypothesis to a true hypothesis. Therefore the principle of avoiding regressive mind changes singles out the generalizing method over the contrary one.