 Rysiew (2000: 577–8) suggested weakening the determinacy condition by replacing “has to believe (and implicate) p” with “is likely to believe (and implicate) p”. As he notes, hearers commonly use abduction to figure out what speakers have implicated (cf. Hobbs et al. 1993). Abduction is a specific form of inductive or non-demonstrative reasoning in which a hypothesis is inferred to be true from the fact that it provides the best explanation of the data. By their nature, non-demonstrative methods are not guaranteed to succeed. This fact of life is no reason to shun induction when seeking to discover implicatures. W. Davis (1998: 66–8) had observed, though, that an implicature can exist and be conversational even though the available evidence does not make that implicature (or belief) more likely than others. Examples like those above with more than two equally likely alternatives show this.