According to the "hypothetico-deductive model of justification" which came to be an accepted element of the empiricist consensus, when observation reveals that the predicted phenomenon occurs as predicted, the law from which it is predicted is "confirmed," or "corroborated," when observation reveals that phenomena do not occur as predicted, the law is "refuted" or "falsified." Prior to any successful predictions, a theoretical statement is purely "hypothetical." Only direct observation statements may be regarded as "verified." Positivists came to accept that all hypotheses are only "confirmed" by the evidence. Falsificationists emphasized that attempts to refute the hypothesis have failed and spoke of the hypothesis as "corroborated." After it has been confirmed by a wide range of successful predictions, and in the absence of any falsifying failed predictions, theoretical statements move from being of a purely "hypothetical" status to being rationally justified and are often called "laws of nature." The difference between a "law" and a "theoretical hypothesis" (or "conjecture") is thus merely the degree of confirmation or corroboration.