A field or method that is offered as as a scientific field or method satisfies the requirements for the admissibility of evidence under Federal Rule 702 or a comparable State rule only if the field or method is shown to be genuinely scientific.

Cameron v. Otto Bock Orthopedic Industry, Inc., 43 F.3d 14, 17 (1st Cir. 1994) (holding, in plaintiff prosthetist customer's action for negligence and breach of warranty, that evidence of "Dear Customer" letters [which provided precise....Although the rule limiting the admissibility of subsequent remedial measures bars the use of subsequent remedial measures to prove negligence, culpable conduct, a defect in the product or its design, or a need for warning or instruction, subsequent remedial measures are admissible to show ownership or control.

Brazos River Authority v. GE Ionics, Inc., 469 F.3d 416, 426 (5th Cir. 2006) ("Although Ionics urges that the district court properly excluded evidence of other fires because the circumstances of the BRA fires were unique, the law in this circuit with respect to cases, such as this case or Davidson, that...To be admissible, prior events or accidents must be substantially similar to those at issue in trial.

Sherman v. United States, 356 U.S. 369, 373-376 (1958) (reversing conviction for the sale of narcotics and remanding to the trial court with instructions to dismiss the indictment because the defense of entrapment was established as a matter of law and the accused was merely induced by the government...A subjective entrapment defense makes an accused's criminal liability contingent on a finding of the accused's predisposition or the accused's lack of predisposition to commit the crime charged and since criminal predisposition is a character trait, the defense of subjective entrapment makes accused's character an element of either a defense or a criminal charge, evidence of accused's criminal predisposition -- including evidence in the form of reputation, opinion, and evidence of specific instances of accused's conduct -- is not barred by the rule against the use of a person's character to show the person's conduct.