The expert’s testimony here regarding the effects of methamphetamine on human behavior was based upon a method of research which involved correlating the driver’s use of methamphetamine with the observations of the driver’s behavior by percipient witnesses in accident cases in Washington State. The prosecution’s expert had published two papers on this subject had been subjected to peer review. The defense expert testified that extrapolations the prosecution made regarding the effect of methamphetamine use on driving behavior could not be made based on these data, and that there were no similar studies. The trial court held that these objections went to weight rather than admissibility, and permitted the testimony. The Court of Appeal upheld the trial court, and found that the expert had used a method generally accepted in the scientific community within the meaning of People v. Kelly (1976) 17 Cal.3d 24. The Court of Appeal further found that the trial court did not abuse its discretion in admitting the expert’s opinion, based on these studies, that a person with defendant’s concentration of methamphetamine in his blood, who demonstrated symptoms like defendant’s, would not have had the ability to drive safely. This expert opinion comported with Evidence Code section 801, subdivision (b).