I recently posted about a local federal decision excluding an expert that the court concluded lacked a methodology. The logic of this opinion was not limited to federal courts. Even Nevada state courts are supposed to require an expert to have something other than their own opinion that their opinion is reliable.
For instance, Brant v. State affirmed the district court’s order excluding a proposed expert who offered no evidence other than her own opinion to establish the reliability of her opinions. “But with no evidence to establish a scientific or other recognized basis for challenging the interrogation techniques utilized in this case … we have only Dr. Krawczyn’s ipse dixit that the techniques possibly used may have influenced Brant’s confession. This is not enough to establish an abuse of discretion in excluding such testimony.” This is substantively similar to the United States Supreme Court’s holdings. “[N]othing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert.”
 130 Nev. 980, 987, 340 P.3d 576, 581 (2014).
 General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997).