Texas Rules of Evidence, Rule 702 provides: If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise. TEX. R. EVID. 702. The court held that Rule 702 requires the proponent to show not only that an expert is qualified, but also that the expert's testimony is relevant to the issues in the case and is based on a reliable foundation. Robinson, 923 S.W.2d at 556. To be relevant, the proposed testimony is subject to the traditional analysis of relevancy under Texas Rules of Evidence 401 and 402, and therefore it must be sufficiently tied to the facts of the case that it will aid the jury in resolving a factual dispute. To be reliable, the scientific techniques or principles underlying the expert's testimony must be well grounded in the methods and procedures of science. Id. at 557. The court set out the following nonexhaustive list of factors a trial court may consider in determining the reliability of the underlying techniques or theories and thus the admissibility of an expert's testimony under Rule 702: (1) the extent to which the theory has been or can be tested; (2) the extent to which the techniques rely on the subjective interpretation of the expert; (3) whether the theories have been subjected to peer review and/or publication; (4) the techniques' potential rate of error; (5) whether the underlying theories or techniques have been generally accepted as valid by the relevant scientific community; (6) the nonjudicial uses which have been made of the theories or techniques. In E.I. du Pont de Nemours & Co. v. Robinson, 923 S.W.2d 549 (Tex. 1995) the plaintiffs claimed that a fungicide damaged their pecan orchard; in Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997), the plaintiff claimed that her use of an anti-nausea drug during pregnancy caused her child's birth defects. The plaintiffs in both cases presented experts testifying that the chemical at issue caused injuries. See Robinson, 923 S.W.2d at 551; Havner, 953 S.W.2d at 708. In Robinson, the trial court excluded the expert testimony and granted a directed verdict for the defendants; in Havner, the trial court admitted the expert testimony. See Robinson, 923 S.W.2d at 558; Havner, 953 S.W.2d at 709. On appeal, the issue in Robinson was whether the court abused its discretion in excluding the testimony, while in Havner the issue was whether the admitted testimony was sufficient to show causation. In Robinson, the Texas Supreme Court addressed the proper standard for the admission of expert testimony under Texas Rule of Evidence 702. See Robinson, 923 S.W.2d at 556.