[Please note: at the time this paper was first published in the Spring of 1997, the Supreme Court had not handed down its decision in G.E. v. Joiner.  Because of the Joiner decision, this paper is now better suited for presenting the differing arguments currently going on in the states as to the method in which Daubert decisions should be reviewed.  To get the current state of the law in light of Joiner, click here.]

Introduction
     The standard of review for an evidentiary ruling under Daubert has been the source of much disagreement in Federal Courts. Since the Supreme Court's decision, Courts of Appeals have struggled to define the scope of the trial court's discretion in rulings on expert testimony.⁽¹⁾ The issue is a divisive one, forcing courts to balance traditional deference to the trial judge on evidentiary matters with the need to delineate the scope of the "gatekeeping" role envisioned by the Supreme Court. A clear, and somewhat troubling split has emerged, the result of which is a significant disparity in legal remedies between circuits.

     The Supreme Court will address this issue next term when it hears Joiner v. General Electric Co.⁽²⁾ The Court will review the Eleventh Circuit's application of a somewhat aggressive standard of review to the District Court's exclusion of expert testimony. Commentators hoping to predict the Court's response face a daunting task as there are currently three doctrines mandating different standards of review. In deciding Joiner, the Court will be faced with the challenge of elucidating the proper balance of decision-making power among the appellate court, the trial judge, and the jury. All eyes will focus on a decision which will in many ways determine the future of expert witnesses in federal courtrooms.

Daubert And Appellate Review
     In Daubert, district court judges were vested with the responsibility of ensuring that expert testimony be grounded in proper scientific methodology appropriate to the particular dispute.⁽³⁾ The Daubert test has several strands. First, the trial judge is to decide whether the reasoning or methodology underlying the testimony is scientifically valid (the reliability prong). Second, the judge is to determine whether or not that particular methodology is properly applied to the facts at issue (the "fit" prong). A final consideration mentioned in Daubert is Federal Rule of Evidence (FRE) 403, which allows the trial judge to exclude testimony which may be prejudicial, confusing, or misleading to the jury.⁽⁴⁾

     On its face, such an analysis would seem to be a factual decision within the discretion of the trial judge and only reversible for clear error. Since each dispute raises unique factual situations and unique experimental evidence, it would seem that the trial judge is best situated to mold the inquiry to the case at hand. Consequently, appellate courts should only disturb these rulings if the trial judge exceeded the bounds of discretion in his or her determination of the reliability and fit of the expert's evidence.

     On the other hand, a decision to admit or exclude expert testimony is one that hinges upon an interpretation of FRE 702, and would thus arguably be a matter of law reviewable de novo by the appellate court. Furthermore, the type of analysis necessary for a Daubert hearing does not hinge on physical testimony but is often "on paper." The Daubert inquiry is geared toward methodology, and a thorough review of methodological materials can arguably be done on a "cold record" just as well as the review of affidavits in the trial judge's chambers. As such, the argument goes, many of the usual reasons for deference to a trial judge's discretion may not be applicable to a Daubert ruling.

     While most courts seem to follow the "abuse of discretion" standard of review, several have decided to look at Daubert rulings de novo, or at least partially so. In addition, some courts apply the simple, discretionary test, but invoke a more stringent review in cases where the exclusion of evidence was dispositive of a claim under Federal Rules of Civil Procedure (FRCP) 50 or 56. Each of these standards has far-reaching implications for the future of modern litigation. In an attempt to familiarize the reader with the issues in Joiner. In an attempt to make things even clearer for the reader an overview of the policy implications of each legal test and a discussion of the issues as they relate to the Supreme Court's task in deciding the case itself will also be included.

The Discretionary Standard
     The majority of courts have held that decisions on the admissibility of an expert witness are clearly within the province of the trial judge's discretion, and will only be overturned for manifest error or abuse of discretion. In Benedi v. McNeil P.P.C., for example, the Fourth Circuit held that Daubert "clearly vests courts with discretion to determine the admissibility of expert testimony" and applied an abuse of discretion standard to evidentiary rulings⁽⁵⁾.

     The discretionary standard has also been applied in the First, Fifth, Eighth, and D.C. Circuits⁽⁶⁾. Just recently, the First Circuit held that "because gauging an expert witness's usefulness is almost always a case-specific inquiry, the law affords trial judges substantial discretion in connection with the admission or exclusion of opinion evidence. Thus, we will uphold the district court's ruling in this area unless it is manifestly erroneous."⁽⁷⁾ The Ninth Circuit, which first applied the Daubert test on remand from the Supreme Court, has held in Lust v. Merrell Pharmaceuticals that "the abuse of discretion standard applies to a F.R.E. 702 ruling even though the ruling was dispositive of a motion for summary judgment."⁽⁸⁾

     The policy arguments supporting this standard are rather straightforward. Broad discretion in admissibility hearings allows the trial judge to make bolder and more intensive analyses of the methodology supporting expert opinions. Free from a body of strict rulings in which he or she is expected to operate, a trial judge is able to apply a "totality of the circumstances" approach to expert testimony, permitting more flexible decisions in complex and controversial cases.

     However, the discretionary standard could conceivably increase litigation costs by requiring constant re-examination of typically unsound methodology. If a particular type of animal study is, for example, not helpful in certain classes of product liability cases, a de novo standard would allow appellate courts to rule, as a matter of law, accordingly. If a genre of study truly is questionable science, it seems wasteful to require several district courts to make the same determination with lengthy hearings. An abuse of discretion standard may invite re-litigation.

Active Appellate Courts And De Novo Review
     In contrast to the courts noted above, the Sixth and Seventh Circuits have taken a far more active role in delineating the requirements of Daubert hearings. In Cook v. American Steamship Co., the Sixth Circuit announced a new standard of review for admissibility of expert testimony under Daubert:

Appellate review . . . may involve as many as three separate standards of review. The trial court's preliminary fact-finding under Rule 104(a) is reviewed for clear error. . . . [T]he court's determination whether the opinion the expert wishes to offer is properly the subject of scientific, technical, or other specialized knowledge" is a question of law we review de novo . . . [F]inally, the trial court's determination whether the proffered expert opinion "will assist the trier of fact to understand the evidence or to determine a fact in issue,". . . is a relevancy determination and therefore one we review for abuse of discretion.⁽⁹⁾
 

     In Borawick v. Shay, the Second Circuit followed the Cook/Bradley reasoning and adopted a "split" test of its own.⁽¹²⁾ In assessing the validity of post-hypnotic testimony, the court noted that "review must be de novo on the question whether, in exercising its discretion to admit evidence, the district court applied the proper test. . . .[W]e review the district court's finding that [the expert] was unqualified for clear error."⁽¹³⁾ The Tenth Circuit adopted a similar approach in Compton v. Subaru, holding that "applicability of the Daubert standard is a question of law; however, once relevance and application of Daubert is determined, a court may reverse only for abuse of discretion."⁽¹⁴⁾

     The "mixed" approach to appellate review has several attractive features. It clearly allows -- indeed mandates -- that there be uniformity among the courts on the range of permissible evidence in federal courts. If the Daubert decision is to have meaning, it would seem that stricter appellate scrutiny should be used to create a body of "questionable science" precedents to assist trial judges in the admittedly complex and confusing morass of analysis involved in a Daubert ruling.

     On the other hand, de novo review undoubtedly limits the flexibility of trial judges. The admission of expert testimony has long been solely within the province of the trial judge, and to mandate certain types of evidentiary rulings seems to trample that discretion. Since modern scientific and technical evidence is complex and increasingly dynamic, there is a strong likelihood that a district court's effectiveness in dealing with novel issues might be overly constrained by appellate decisions.

The "Hard Look" Standard
     Some courts have sought to balance the two extremes. The Third Circuit has adopted an abuse of discretion standard, but with a more intense standard of review if the exclusion of the evidence would result in a dispositive motion under FRCP 56 or 50. The court held that "if exclusion of expert testimony will result in a summary judgment or a judgment as a matter of law, appeals court will give rulings a "hard look" to determine if the court has abused its discretion.⁽¹⁵⁾ The court justified this approach by noting that there is a danger that district judges might set the standard too high, and essentially force parties to try their case twice.⁽¹⁶⁾

     In Joiner, the Eleventh Circuit seems to have fused the discretionary test with the "mixed" Cook test, adopting a rule similar to that of the Third Circuit.⁽¹⁷⁾ The court held that the "abuse of discretion" standard applied to Daubert hearings, but due to the Federal Rule's preference for liberal admissions, appellate review of excluded expert testimony would be "particularly stringent."⁽¹⁸⁾ Insofar as the ruling turned on interpretation of a FRE, however, the court's review would be plenary.⁽¹⁹⁾ Citing both Paoli and Cook, the court went on to reverse the District Court's grant of summary judgment and its decision to exclude all of the plaintiff's expert testimony.⁽²⁰⁾

     Although similar to the Cook/Bradley line of doctrine, the Joiner test has several distinctive characteristics. First, the test only seems to be invoked when evidence is excluded.⁽²¹⁾ In cases where an expert's testimony was admitted, the "stringency" standard wouldn't seem to be applicable. Accordingly, an erroneous decision to admit expert testimony has a far greater likelihood of going unnoticed than a questionable exclusion. Second, the plenary review would only seem to initiate when the trial judge rooted a particular decision in the FRE themselves.⁽²²⁾ However, since every "scientific" expert arguably invokes the Rules, rulings on expert testimony would always seem to invite plenary review, at least to some degree. Because a Daubert hearing invariably turns on both factual and legal distinctions, the question, still unresolved, is exactly which part of the ruling is "interpretive" and which is "discretionary."

     A potential problem with the Joiner test is that there seems to be no limit on how "hard" the court's "look" will become. The court does not seem to draw a line between "particularly stringent" and de novo review. Thus while the test seems to reserve deference to the trial judge's findings, there is no prophylactic rule ensuring this result.

Joiner And The "Hard Look" Standard
     The Joiner court's application of the "hard look" test demonstrates its fluidity. In assessing the plaintiff's claims that polychlorinated biphenyls (PCBs) caused his lung cancer, the majority applied a rather narrow definition of judicial "discretion." Mr. Joiner, an electrician who repaired electrical transformers and voltage regulators containing PCB-based dielectric fluid, presented several experts who testified as to the link between PCB and the onset of his lung cancer. The District Court excluded the experts' testimony after they failed to meet both the "reliability" and "fit" requirements of Daubert.⁽²³⁾

     Joiner's witnesses testified that PCB "dioxins" and "furans" (chemical derivaties of PCB which are usually present when PCB is exposed to extremely high temperatures in the presence of oxygen) were known carcinogens and consequently promoted Mr. Joiner's lung cancer.⁽²⁴⁾ In addition to numerous journal studies supporting their conclusions, the experts also presented the results of recent animal studies linking PCB to cancer in lab mice.⁽²⁵⁾

     The District Court Judge, Orinda D. Evans excluded one set of experts' testimony because Joiner failed to show that he had been exposed to PCB and dioxins/furans.⁽²⁶⁾ Because there was no evidence that the fluid was ever heated above a certain temperature, there was no evidence that dioxins or furans were present. Without sufficient proof of exposure to those elements, Evans ruled that the expert testimony did not "fit" the facts of the case.⁽²⁷⁾

     Evans also ruled that the testimony relying on the animal studies was inadmissible because: (1) the animal studies were only "preliminary" and (2) they involved PCB levels much higher than those of Mr. Joiner's alleged exposure. These shortcomings led Evans to believe that the "reliability" prong of Daubert had not been satisfied.⁽²⁸⁾ The Eleventh Circuit reversed both of the evidentiary rulings, as well as the grant of summary judgment⁽²⁹⁾.

     In finding that the testimony was erroneously excluded, the Court of Appeals noted that the defendants had not foreclosed the possibility that dioxins and furans could have been present.⁽³⁰⁾ One expert noted that a transformer struck by lightning may have been heated beyond the required point, and Joiner occasionally worked on equipment damaged in electrical storms. This, according to the court, was enough evidence to conclude that the testimony "fit" the facts of the case.⁽³¹⁾ The court also noted that the decision to exclude the animal studies was inappropriate because it went beyond a mere evaluation of the "methodology" behind the studies and instead assessed their conclusions.⁽³²⁾

     In reaching these conclusions, the court seemed to apply a de novo standard of review to both the reliability (animal studies) and fit (dioxin/furan) assessments of the trial judge. The court's test, however, purports an application of the discretionary standard. Note that even the Sixth Circuit's Cook test requires that the "fit" rulings of the trial court be evaluated only for abuse of discretion.⁽³³⁾

     In a rather vigorous dissent, Senior Circuit Judge Smith argued for a clearer standard, imploring the court to adopt the more explicit test of the Sixth and Seventh Circuits.⁽³⁴⁾ After attacking the majority's decision to admit the expert testimony, Smith noted that the court's "hard look" test, while attractive on its surface, provides little or no guidance to lower courts. The Sixth Circuit test, he argued, is much clearer and easier to understand, forcing lower courts to frame their inquiry in terms that can be uniformly evaluated by both appellate and other courts seeking guidance.⁽³⁵⁾ If followed in this case, Smith believed that the Sixth Circuit test mandated the affirmation of the lower courts rulings.

     Thus while the Joiner test, on its face, seems to be rather traditional, it has the potential to make sweeping changes in the courtroom. The clear message of the Eleventh Circuit is that the judge's "gatekeeping" role is to be a narrow one. Only the most speculative evidence should be withheld from a jury's consideration.

Conclusion
     Each of the three approaches reflects, to some degree, the standpoint of the court on exactly how much "new" testimony will be tolerated. The "mixed" test will, most likely, result in a stricter application of the Daubert framework, and may very well narrow the scope of "novel" expert testimony in federal courts. In contrast, the "modified" tests of the Third and Eleventh Circuits, because they focus on excluded evidence only, have the potential to be very liberal. Finally, the abuse of discretion test is rather unpredictable. With discretion left to the trial judge, the tone set by federal jurisdictions will vary from courtroom to courtroom. The Supreme Court's decision in Joiner should clarify the standard set out in Daubert, and the Court's vision of "gatekeeping," should become clearer when this case is decided.

1. Six Circuits currently apply an "abuse of discretion" standard, two apply a "stringent look" standard, and four apply a mixed, "de novo" and "clear error" test.
2. 78 F.3d 524 (11th Cir. 1996).
3. Daubert v. Merrell Dow Pharmaceuticals, 113 S. Ct. 2786, 2796, 125 L. Ed. 2d 469 (1993).
4. Id. at 2698.
5. 66 F.3d 1378, 1384 (4th Cir. 1995).
6. See generally, Pedraza v. Jones, 71 F.3d 194, 197 (5th Cir. 1995), United States v. Kayne, 90 F.3d 7, 11 (1st Cir. 1996), United States v. Dorsey, 45 F.3d 809, 812-815 (4th Cir. 1995), Hose v. Chicago NorthwesternTransportation Co., 70 F 3d 968, 972 (8th Cir. 1995), Joy v. Bell Helicopter Textron, Inc., 999 F.2d 549, 567 (D.C. Cir. 1993).
7. Bogosian v. Mercedes-Benz, 1997 WL 3276 *3 (1st Cir.(R.I.)).
8. 89 F.3d 594 (9th Cir. 1996).
9. 53 F. 3d 733, 738 (6th Cir. 1995) (emphasis added).
10. 42 F.3d 434, 436 (7th Cir. 1994).
11. Id. at 436-437.
12. Borawick v. Shay, 68 F.3d 597, 601 (2d Cir. 1995).
13. Id. at 601.
14. 82 F.3d 1513, 1517 (10th Cir. 1996).
15. In Re Paoli Railroad Yard PCB Litigation. 35 F. 3d 717, 749 (3d Cir. 1994), see also DeLuca v. Merrell Pharmaceuticals, 911 F. 2d 941, 944 (3d Cir. 1990) (holding that, to the extent a court interprets a Federal Rule of Evidence, appellate review is plenary).
16. In Re Paoli Railyard PCB Litigation, 35 F.3d at 750.
17. 78 F.3d 524 (11th Cir. 1996).
18. 78 F. 3d 524, 529 (11th Cir. 1996).
19. Id.
20. Id. at 534.
21. We apply a particularly stringent standard of review to the trial judge's exclusion of expert testimony." Id. at 529.
22. Id. at 529.
23. 864 F.Supp 1310, 1326.
24. Id. at 1322.
25. Id. at 1324.
26. Id. at 1322.
27. Id.
28. Id. at 1324.
29. 78 F.3d 524, 534.
30. Id.
31. Id.
32. Id. at 533.
33. 53 F. 3d 733, 738 (6th Cir. 1995).
34. Id. at 535. (SMITH, Senior Judge, Dissenting.).
35. Id. at 535.