  In the linguistic case, what sometimes seems to underpin people's  positions on such issues is differing intuitions as to who has the  burden of proof in this debate. Empiricists or non-nativists contend  that Chomskyans have not presented enough data (or considered enough  alternative hypotheses) to establish their case. Chomskyans reply  that they have done more than enough, and that the onus is on their  critics either to produce data disconfirming their view or to produce a testable alternative to it.