 In a somewhat similar vein, Daniel Rothbart (1990) emphasized the distinction between the standards to be used when testing a theory and those to be used when determining whether a theory should at all be tested. The latter, the eligibility criteria, include that the theory should encapsulate the explanatory success of its rival, and that it should yield testable implications that are inconsistent with those of the rival. According to Rothbart, a theory is unscientific if it is not testworthy in this sense.