 In hypotheticodeductivism, the HD model, one introduces some explanation or principle from any source, such as imagination or even a dream, infers logical consequences of it—that is, deductive inferences—and compares those with observations, perhaps experimental.In simple or Whewellian hypotheticodeductivism, one might accept a theory as metaphysically true or probably true if its predictions display certain traits that appear doubtful of a false theory.In Popperian hypotheticodeductivism, called falsificationism, although one aims for a true theory, yet focuses on dispoving it, prioritizing risky predictions that seem likeliest to fail, and even if the theory succeeds, one never accepts it as true, but regards it as, at best, strongly corroborated.