knowledge and 'technical' or 'other specialized' knowledge." Although Daubert dealt only with scientific knowledge, that was the nature of the case, and it did not stray beyond the facts of that case. The Court observed that the line between "scientific" and "technical" knowledge is not always clear. "Pure scientific theory itself may depend for its development upon observation and properly engineered machinery. And conceptual efforts to distinguish the two are unlikely to produce clear legal lines capable of application in particular cases." If the line between "scientific" and "technical" knowledge was not clear, then it would be difficult for federal trial judges to determine when they were to perform Daubert'''s gatekeeping function and when to apply some other threshold test the Court might craft for applying Rule 702. Furthermore, the Court saw no "convincing need" to draw a distinction between "scientific" and "technical" knowledge, because both kinds of knowledge would typically be outside the grasp of the average juror. Accordingly, the Court held that the gatekeeping function described in Daubert applied to all expert testimony proffered under Rule 702.Daubert had mentioned four factors that district courts could take into account in making the gatekeeping assessment—whether a theory has been tested, whether an idea has been subjected to scientific peer review or published in scientific journals, the rate of error involved in the technique, and even general acceptance, in the right case. In the context of other kinds of expert knowledge, the Court conceded, other factors might be relevant, and so it allowed district judges to take other factors into account when performing the gatekeeping function contemplated by Daubert. These additional factors would, of course, depend on the particular kind of expert testimony involved in a particular case. Equally as important, because federal appeals courts review the evidentiary rulings of district courts for abuse of discretion, the Court reiterated that district courts have a certain latitude to determine how they will assess the reliability of expert testimony as a subsidiary component of the decision to admit the evidence at all. Applying that standard to the evidence proffered by the Carmichaels' tire expert, the Court concluded that the district court correctly refused to admit the expert's testimony. The district court had to determine whether the tire expert's methods could reliably determine what had caused the tire on the Carmichaels' van to explode. The expert's experience as a tire engineer wasn't the problem—the