In Daubert v. Merrell Dow, the Supreme Court suggested that judges confronted with a challenge to scientific testimony at trial should undertake "a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue."⁽¹⁾ The Court, however, failed to enumerate precisely how trial courts were to accomplish this goal. Left only with the Court's broad discussion of the Federal Rules of Evidence in Daubert, jurists have attempted to devise a procedural framework within which to make this assessment. This framework includes: Rule 702's admissibility tests, Rule 703's allowance of otherwise inadmissible facts or data, Rule 403's balancing of probative value against possible prejudice or confusion, Rule 706's standards for the appointment of experts to assist the judge, and especially Rule 104(a)'s provisions establishing that such assessments be preliminary in nature.⁽²⁾

     Left with such vague procedural guidelines, courts have developed a variety of ways in which to conduct the admissibility analysis mandated by Daubert:

The Daubert issue has been raised in motions in limine, motions to strike, and motions for summary judgment. The issue has been raised by a request for a pretrial Rule 104(a) hearing. It has been raised by objection during trial. If the jury is to be kept from hearing the expert's testimony, the objecting party's last chance is an objection during trial, perhaps coupled with a request to interrupt the direct examination and conduct a voir dire examination of the witness to establish that the witness is unqualified or that either the theory or methodology is unreliable or irrelevant.⁽³⁾

Who Should Initiate the Admissibility Inquiry, the Parties or the Court?
     Most courts have required that the party seeking to exclude particular expert testimony must initiate such procedures by motion. Courts have cited conservation of judicial resources as the primary benefit of requiring the parties to initiate Daubert inquiries.⁽⁴⁾ In addition, such a requirement balances the liberal thrust of the Rules of Evidence and the restrictive gatekeeper function of Daubert by ensuring that scientific evidence retains the presumption of admissibility until brought to task by opposing counsel.⁽⁵⁾

     A minority of courts have interpreted Daubert to require that they evaluate proffered testimony sua sponte. Specifically, the First Circuit ruled that "even in the absence of a motion or objection by a party, Daubert requires trial courts to conduct a preliminary assessment of the reliability of expert testimony."⁽⁶⁾ More recently, Judge Robert Maloney of the Northern District of Texas unilaterally threw out the testimony of a plaintiff's damages expert because he considered the testimony "speculative at best."⁽⁷⁾ Judge Maloney went on to say that he doubted the "testimony would have survived a Daubert challenge had one been made."⁽⁸⁾ The desirability and legitimacy of such a judicial activist regime is a matter of considerable contention.

     Proponents of sua sponte review would argue that it affords judges a more activist role in gatekeeping and is thereby in the true spirit of Daubert. If the Court's intent in Daubert was to keep unreliable science out of the courtroom then the judge should be within his or her discretion to employ whatever procedural means necessary to attain this end. Accordingly, Daubert questions could be treated as privileged questions similar to issues of jurisdiction that are often ruled on sua sponte. Just as judges perform an activist gatekeeping role in bringing up jurisdictional issues to dispose of improperly brought cases, so too could they actively dismiss evidence lacking scientific validity. A move such as this could save the court's resources and prevent "circus trials" where bad evidence is put before juries because of opposing counsel failure to question its validity by motion. 

     On the other hand, sua sponte review might encourage parties to forego Daubert inquiries altogether in the hope that the trial judge will take it upon him/herself to inquire into the admissibility of proffered evidence. As a result, courts might find themselves with less information to judge the validity of particular scientific testimony, since they will not have the documentation or testimony that normally accompanies parties' various motions to exclude evidence. Courts would then be required either to elicit this information from the parties or conduct their own investigations perhaps using court-appointed experts or specially trained magistrates.

Should the Determination of Admissibility Occur Before or During Trial?
     Those who favor pretrial determination of admissibility argue that an early evaluation of expert testimony serves to introduce the judge to the vocabulary of the science at issue and thereby ensure his or her familiarity with the evidence. In addition, a timely motion for summary judgement could be granted or a settlement reached that could save both plaintiffs and defendants from potentially needless litigation expenses if critical evidence is excluded as a result of a pretrial Daubert inquiry. Finally, having admissibility issues decided before a jury is seated could save both the jury's and the court's time by preempting the submission of time-consuming, inadmissible expert testimony.⁽⁹⁾

     In bench trials, however, the advantages of an early determination no longer seem to apply. Absent a jury there is no significant difference between an admissibility determination made at a pretrial hearing and one made during the trial. Since the judge will have to examine the evidence as presented in order to make a finding of fact, he will by necessity become familiar with the evidence of the case. The addition of another procedural layer would almost certainly prolong the trial. One could imagine a judge ruling in favor of admissibility in a pretrial motion and then ruling to dismiss the same evidence at trial after the discovery process and further testimony have demonstrated that the evidence is indeed inadmissible. In such instances the initial Daubert inquiry would be a premature expenditure of judicial resources. Judicial economy is best served by conducting admissibility determinations as these determinations are brought to the judge's attention during a bench trial.⁽¹⁰⁾ At the same time, the judge could structure the inquiry such that crucial testimony is examined early in the process. This could ensure that if a party falls short of meeting its evidentiary burden on a key issue then the case could be resolved quickly by summary judgment or a directed verdict.

What is the Burden of Proof for Admissibility and Who Should Bear it?

     The Federal Rules of Evidence mandate an approach for scientific evidence that is similar to the business record or public record hearsay exceptions:

The Court's analysis in Daubert suggests that scientific expert testimony requires the same treatment--the evidence should be presumed to be admissible until the opponent discharges its burden to show the contrary. There is one important difference. Unlike the hearsay exceptions which place the burden of persuasion on the opponent of the evidence with regard to lack of trustworthiness, Rule 104(a) requires the burden of persuasion to remain with the profferer. Accordingly, the defendant only has to shoulder the burden of coming forward with evidence showing that the plaintiff's expert proof is inadmissible. Plaintiff bears the burden of showing by a preponderance of the evidence that the expert's opinion is admissible.⁽¹¹⁾

Are Court-Appointed Experts Formal Witnesses Or Informal Technical Advisors?
     The Daubert decision suggested that a judge could utilize an expert to assist her in the gatekeeping task of evaluating the complicated scientific methodologies of each party's experts. These court-appointed experts take two basic forms: a formal expert witness or an informal technical advisor. To understand the differences between them, we must first determine which of two main sources of authority the judge can use to appoint the expert. Rule 706 of the Federal Rules of Evidence outlines the full set of formal procedures for using a court-appointed expert witness. The rules require that the expert be notified of his duties in writing, advise the parties of any findings, can be deposed by the parties, and may be called to testify or be cross-examined.⁽¹³⁾ Under this regime, the expert acts like a formal witness.⁽¹⁴⁾ On the other hand, the court can also rely on its "inherent authority" established by the common law to appoint a "technical advisor."⁽¹⁵⁾ The role of a technical advisor to the court is less like a witness that makes official findings and more like a private counselor that makes recommendations to the judge. There is also the potential for technical advisors to make secret reports to the judges that will not be released for the parties to challenge. 

    One final question is whether the Daubert decision overruled United States v. Reilly, such that all experts must now be appointed according to Rule 706.⁽¹⁶⁾ Because the Court in Daubert wanted to "reassure judges that they have effective tools to accomplish their difficult gatekeeping task," it is unlikely that the Court wanted to impose such a constraint to force strict adherence to the confines of Rule 706.⁽¹⁷⁾ It is still true, however, that Rule 706 could be used as a guidepost to improve the function of technical advisors.

     Although there are no formal rules constraining the duties of technical advisors, two sound recommendations may improve the use of experts retained under the inherent authority of the Court. 

A. Appoint Technical Advisors Selected by the Parties
     Technical advisors can increase the confidence both parties have in the process. As described below, this device may reduce bias and can be accomplished by the judge having the parties submit lists of acceptable candidates and then working through the lists with the parties to select a compromise expert.⁽¹⁸⁾

B. Allow the Parties to Help Define the Technical Advisor's Duties
     As in Rule 706, this procedure forces the parties to set forth the precise issues upon which they disagree. It will reduce the risk of the advisor "usurping the judge's decision making authority," and it helps set appropriate limits on the advisor's role.⁽¹⁹⁾ These steps will make the process more legitimate by giving the parties a greater role and reducing the possibility for secret reports and meetings with the judge.

How to Find an Expert
     While Daubert suggests that judges can facilitate their gatekeeping duties by relying on experts to assess scientific methods, judges still face the potentially time consuming task of finding suitable experts. One of the main problems in this selection process is ensuring that the expert has no hidden agenda or ideology that could bias her assessment of the evidence. Judges also encounter the problem of not knowing where to find an expert who is both familiar with the topic at hand and willing to serve the court.⁽²⁰⁾ The approaches discussed below attempt to address these problems.

A. Use Pre-Existing Personal or Professional Contacts to Find an Expert
     This method has the advantage of lowering judicial information costs associated with background assessments of an expert's qualifications and neutrality. There are also some possible deficiencies in using this approach. If the judge limits herself to contacts obtained from prior practice or casework, the range of opinions may be so narrow that the process would be inherently biased. The parties themselves may also perceive this process as biased even if the expert is suitable.⁽²¹⁾

B. Contact Nearby Institutions to Aid Search for Suitable Experts
      For example, a judge could call local medical schools and hospitals to find medical expertise. While it may be a cumbersome method to use, it may work better than using informal contacts.⁽²²⁾

C. Enlist the Assistance of Parties
     This method seems to be the most equitable to the parties and to the preservation of the ideals of the adversary system. Many published cases "suggest that a court direct the parties to seek agreement on an appointment and exercise its discretion only if the parties fail to agree."⁽²³⁾ Both sides can submit a list of acceptable experts, and in many cases, the same people may appear on both lists. In the event that there are no matches, judges can still work from the lists to find a compromise candidate.

     There are some final considerations about selecting experts. It is useful for the judge to determine from the very start of litigation whether experts will be necessary so he will have the time necessary for careful evaluation of potential experts.⁽²⁴⁾ Also, the suggestion to use an expert usually comes from the judge herself and not from the parties; in such cases the judge has wide discretion in timing and powers to select the expert.⁽²⁵⁾

Who Will Pay the Experts?
     Payment of technical advisors and court-appointed experts seems to be one of the more serious issues which judges face. This is largely because Rule 706 and Daubert itself are silent on the precise method to use to allocate costs and compensate the experts. Because of this uncertainty and potential for disputes, many judges may feel reluctant to employ the services of experts. There are four general schemes outlined below that may guide judges in deciding how to compensate experts.⁽²⁶⁾

A. Compensation from Public Funds
     In certain cases such as land condemnation cases and criminal cases, Rule 706 and acts such as the Criminal Justice Act authorize the payment of experts from public funds.⁽²⁷⁾

B. Payment by Parties
     Under Rule 706(b), the court has full discretion to determine how the costs will be apportioned. It would probably be best to compensate the expert when the services are rendered instead of waiting until the end of litigation. Therefore, the party most able to pay could be asked to pre-pay the entire fee with the final award considerations taking this pre-payment into account. Most judges require the parties to split the expert's fee, with the prevailing party being reimbursed after the decision.⁽²⁸⁾ If the expert is going to be used for an extended period of time, the parties may be compelled to make periodic payments. Ultimately, these are merely suggestions, and the judge can allocate the costs as fairness and common practice dictates.⁽²⁹⁾

C. Payment When One Party is Indigent.
     When it is impossible for both parties to the share the cost, judges have been hesitant to use experts. There are some precedents, however, where judges have been willing to impose these expenses on the non-indigent party when the other party's claim has merit. For example, in a case where a family claimed to be exposed to toxic substances, the judge wanted an expert to evaluate the defendant's questionable expert testimony and possible disputes were avoided when the defendant agreed to pay for the court's expert.⁽³⁰⁾

D. Technical Advisors
     The main problem with getting the parties to pay for technical advisors is that these advisors can confer in private with the judge and are not expected to give testimony. In a few cases the Administrative Office of the U.S. Courts has been willing to pay for these services. They will, however, generally refuse to pay when the expert could have been appointed according to Rule 706 of the Federal Rules of Evidence or Rule 53 of the Federal Rules of Civil Procedure.⁽³¹⁾

Should Gatekeeping Questions Be Removed From The Trial Courts And Delegated To Special Daubert Judges Or Magistrates Who Have Scientific Training?
     The Supreme Court in Daubert expressed its confidence that judges possess the capacity to undertake the review of expert scientific testimony. It also indicated that they could use neutral experts such as scientists to help them perform their task. The "suggestion that judges rely on the aid of scientists when screening scientific evidence conflicts with its [Supreme Court] mandate that judges make their own reliability determinations."⁽³²⁾ Additionally, as technology continues to progress, these hearings will no doubt increasingly focus on scientific methods and issues of heightened complexity. Future hearings may take too much of the court's time and resources and the complexity of these hearings may lead to widely divergent rulings in the same jurisdiction.

     One remedy to this problem would be to establish a class of Daubert judges whose sole responsibility would be to assess scientific evidence in accordance with the standards set by the Daubert decision. These judges would already have experience and training in science, and through their handling of a large volume of Daubert hearings over time, they would develop a better feel for the proper bounds of judicial gatekeeping. This would not only be more efficient, but it would lower the costs of Daubert hearings and produce more consistent decisions. Assessing the biases of expert witnesses would also be unnecessary because judges are by definition neutral and disinterested. Opposing parties may also be more willing to accept the decision of a scientist-judge rather than the recommendations of a court-appointed expert, whose opinion a lay judge may often rubber-stamp rather than scrutinize.

     Margaret G. Farrell envisions the use of "special masters" with scientific training in the evaluation of expert scientific testimony.⁽³³⁾ They can be appointed either through "legislation providing for the appointment of magistrates as masters" or through Rule 53 of the Federal Rules of Civil Procedure.⁽³⁴⁾ Rule 53(b) authorizes the appointment of a special master in jury cases when the issues are complicated and in non-jury cases when an exceptional circumstance requires it. Judicial review of a special master's decision would have to come from the writ of mandamus. Additionally, as the system is currently structured these masters do not have to be full-time jurists. They can be law professors or other people with expertise in a relevant area. Perhaps the best approach to this innovative proposal would be to have the legislature formalize the position, at once legitimizing it and placing greater controls upon it.

     On the downside, this approach seems to "pass the buck" to these specialized judges when the Supreme Court in Daubert believed that all trial judges are capable of fulfilling the gatekeeping task. Additionally, these special masters raise the specter of an elite class of judges largely impervious to judicial review because of the complexity and specialization of their training. In this case, unforeseeable biases may sneak into the system and would be hard to detect. The use of Daubert judges or special masters may merit additional consideration and possibly use in exceedingly complex cases, but for the time being it seems prudent to have our trial judges remain in their role as gatekeepers.

1. Daubert v. Merrell Dow Pharmaceuticals, 113 S. Ct. 2786, 2796 (1993).
2. See Lee Loevinger, Commentary on "Evidentiary Framework," 36 Jurimetrics J. 149, 152-55 (1996).
3. G. Michael Fenner, The Daubert Handbook: The Case, Its Essential Dilemma, and Its Progeny, 29 Creighton L. Rev. 939, 984 (1996).
4. Margaret A. Berger, Procedural Paradigms for Applying the Daubert Test, 78 Minn. L. Rev. 1345 (1994), reprinted in ALI-ABA Course of Study: Civil Practice and Litigation Techniques in the Federal Courts, C947 ALI-ABA 1, 25 (1994).
5. Id. at 23.
6. Stephen P. Groves & Reagan W. Simpson, Recent Developments in Civil Evidence and Procedure, 31 Tort & Ins. L.J. 169, 174 (1996) (citing Hoult v. Hoult, 57 F.3d 1 (1st Cir. 1995)). 
7. J. Stratton Shartel, Daubert Burns Both Sides in Sun Tan Litigation, 10 No. 9 Inside Litig. 1, 1 (1996) (citing Supre Inc. v. California Suncare Inc., No. 394 CV 0503-T, (N.D. Tex, 1996)).
8. Id.
9. See Fenner, supra note 3, at 957.
10. Case v. United School District No. 233, 895 F.Supp. 1463, 1472 (D. Kan. 1995).
11. Berger, supra note 4, at 23.
12. See Fenner, supra note 3, at 1020.
13. Fed. R. Evid. 706.
14. See In re Breast Implant Cases, 942 F.Supp. 958 (S.D.N.Y. 1996) (where the court mentions Judge Sam Pointer, Jr.'s creation of a national committee of experts appointed under Rule 706 to help the breast implant cases). 
15. Ex parte Peterson, 253 U.S. 300 (1920) (where the Supreme Court upheld the inherent powers of a trial judge who had appointed an expert auditor to investigate facts, interview the parties, hold hearings, and submit a report to the court containing the auditor's own opinions); see also United States v. Reilly, 863 F.2d at 149 (1st Cir. 1988) (holding that the enactment of the Federal Rules of Evidence which contains Rule 706 did not displace the inherent authority of a court to appoint technical advisors).
16. The Court's reference to Rule 706 is as follows: "Throughout, a judge assessing a proffer of expert scientific testimony . . . should also be mindful of other applicable rules . . . Rule 706 allows the court at its discretion to procure the assistance of an expert of its own choosing." Daubert, 509 U.S. at 955.
17. Improving Judicial Gatekeeping: Technical Advisors and Scientific Evidence, 110 Harv. L. Rev. 941, 952 (1997).
18. Id. at 954.
19. Id. at 956-57.
20. Joe S. Cecil & Thomas E. Willging, Accepting Daubert's Invitation: Defining a Role for Court-Appointed Experts in Assessing Scientific Validity, 43 Emory L. J. 995, 1022 (1994).
21. Id. at 1023.
22. Id. at 1024.
23. Id. citing Superior Beverage Co., No. 83 C 512, 1987 WL 9901 (N.D. Ill. Jan. 30, 1987), United States v. Michigan, 680 F.Supp. 928, 957 (W.D. Mich. 1987).
24. Id. at 1020.
25. Id. at 1021.
26. Id. at 1046.
27. Id. at 1047.
28. See Hall v. Baxter Healthcare Corp., No. 92-182-JO, 1996 WL 730693, at *2 & *76 n.9 (D.Or. Dec. 18, 1996). 
29. Cecil & Willinging, supra, note 18 at 1048-51.
30. Id. at 1052-53.
31. See Reilly v. United States, 682 F.Supp. 150 (D.R.I), aff'd in part, 863 F.2d 149 (1^st Cir. 1988) (where the district judge petitioned the Director of the Administrative Office for permission to appoint and pay a technical advisor.) This request was granted, and it seems that although it is still an unusual request, it may become more common as courts use experts for personal technical assistance and not testimony. 
32. 509 US at 946.
33. Margaret G. Farrell, Coping with Scientific Evidence: The Use of Special Masters, 43 Emory L. J. 927 (1994).
34. Id. at 944-45.