Daubert: 10 Years Later

The initial point of deposition attack should be the expert's qualifications. Daubert stated that the court must determine whether the proffered testimony “fits” the facts of the case. The determination of “fit” is, in essence, a relevance inquiry that requires a showing of more than bare relevance. See In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 745 (3d Cir. 1994). The qualifications of the expert should be explored to determine whether the body of knowledge in which they claim expertise fits the case. For example, a court disqualified a mechanical engineering expert in an electrical shock case because he was not an electrical engineer. See Trumps v. Toastmaster Inc., 969 F. Supp. 247, 252 (S.D.N.Y. 1997).

The expert should be questioned concerning all of the data upon which he or she relies, with the goal of showing that some relevant data have not been included, or some data are unreliable. Failure to consider all relevant data in forming an opinion is a basis for finding them unreliable. See United Phosphorus, Ltd. v. Midland Fumigant, Inc., 173 F.R.D. 675, 683-84 (D. Kan. 1997). The requirement of Rule 703, Fed. R. Evid., that supporting data be of the type reasonably relied upon by other experts in the field, should also be kept in mind. If an expert relies on unreliable data, he or she should be thoroughly questioned on whether other experts in the field rely on such data, and their basis for such reliance. Even if other experts rely on the data, the reasonableness of the reliance can be challenged. For example, reliance on Consumer Product Epidemiological Investigation Reports, which are reviewed by experts in many cases, has been successfully challenged because they contain unreliable hearsay statements. See Knotts v. Black & Decker, Inc., 204 F. Supp. 2d 1029, 1041 (N.D. Ohio 2002). The expert should be examined concerning all documents that contain the data upon which he or she relies, and the documents should be produced if they have not been up to that point. Even if an expert makes a facial assertion that the opinion is based on reliable data, further examination may reveal otherwise. For example, the expert may claim to base his or her opinion on testing. Such testing may have been conducted for other cases in which the expert was advocating a similar position, or records of the testing may not exist.

All assumptions made by the expert should be scrutinized. A careful examination of his or her opinion will often reveal totally unsupported assumptions. As an example, experts in fire cases many times assume that a product can ignite a fire without knowing the temperature the product can generate, or the ignition temperatures of surrounding combustibles. Similar assumptions are made in many other types of cases. Unwarranted assumptions are an accepted basis under Daubert for disqualifying an expert. See Boucher v. United States Suzuki Motor Corp., 73 F.3d 18, 21 (2d Cir. 1996).

The precise methodology used by the expert to formulate his or her opinion should be established. In many cases, the methodology will consist of no more than an inspection of the product and an application of alleged scientific or technical principles to knowledge gained from the inspection. In cases where the product is alleged to have caused a disease, experts commonly review the plaintiff's medical records and apply assumptions based on epidemiological studies to those data. If the expert's methodology was only reviewing a product or data, and applying alleged principles, he or she should be required to state that fact. A concise statement of the methodology by the expert will assist the court in assessing its reliability.

Once the methodology is identified, the following five factors identified in Daubert are the starting point for assessing its reliability:

• whether a theory or technique has been or can be tested;
• whether it has been subjected to peer review and publication;
• whether there are standards for its application;
• whether it has a known or potential error rate; and
• whether it is generally accepted within a relevant expert community.

Not all factors may apply to the testimony of a particular expert. Counsel should assess which factors reasonably may be applied. Because expert testimony concerning liability issues in products cases is generally scientific or technical, all of the Daubert factors usually will be a reasonable source of deposition questions.

Some courts have stated that testing or testability is the most important Daubert factor in a reliability inquiry. See Bradley v. Brown, 42 F.3d 434, 438 (7th Cir. 1994). The expert should be required to describe thoroughly all testing conducted to substantiate his or her conclusions. The expert should then be questioned concerning any other relevant testing he or she can imagine that could be conducted. If he or she can identify other available tests, the attorney should ask why the expert has not conducted them. If the expert cannot identify a way to test, he or she should be required to state that the stated opinion is not testable.

Even when testing is conducted, it may not “fit” the facts of the case. The expert should be challenged to explain why the testing shows anything relevant concerning the case. In a recent case, a purported expert tried to prove that food could jam a product's mechanism by himself jamming the mechanism with a metal object. The “testing” obviously did not fit the case facts, because a metal object in no way simulated the food that allegedly jammed the product.

Continuing the Daubert factor questioning, the expert should be asked whether his or her methodology has been peer-reviewed and published, and what standards exist for its application. If the expert has only inspected a product and formed his or her own opinion, it is unlikely that he or she will be able to identify any publications or standards to support that methodology. The opinion may then be attacked on the grounds that it is based on an unverifiable methodology and is really just result-oriented advocacy. Likewise, the expert should be asked to identify peer-review, publishing, and standards for the underlying principles and knowledge that he or she is purporting to apply to the facts of the case.

Questions about the error rate of the methodology can produce particularly interesting answers. An expert should be asked to state how often the methodology produces incorrect results. Experts are often not prepared to answer questions concerning error rate, but a known error rate is essential to assessing reliability. If an expert testifies that he or she has never erred, an error rate cannot be calculated, and the expert's credibility may be diminished.

The expert should be questioned about the final Daubert factor, whether his or her methodology is generally accepted in the field. If the methodology is accepted, according to the expert, the basis for that assertion should be explored. The expert should be required specifically to identify other authorities who use the methodology so that the extent of acceptance can be determined.

The inquiry should not stop with the original five Daubert factors. Case law reveals many other factors that may be considered. For example, questions concerning potential alternate causes of the accident or illness should be asked in many cases. Failure to account for alternate causes can render a methodology unreliable. See Claar v. Burlington N.R.R. Co., 29 F.3d 499, 502 (9th Cir. 1994). The precise standard for elimination of a potential cause should also be stated. The uniform application of the standard will also often lead to the elimination of the thing the expert identified as a cause. The expert should be asked whether he conducted the work in the same manner as his non-litigation work. A failure to do so indicates unreliability. Sheehan v. Daily Racing Form, Inc., 104 F.3d 940, 942 (7th Cir.), cert. denied, 521 U.S. 1104 (1997). Likewise, reliance on research conducted solely for litigation also indicates unreliability. See Daubert v. Merrill Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1317 (9th Cir.), on remand from, Daubert, 509 U.S. 579 (1995). The inquiry should not end with the factors listed here. Kumho's flexible inquiry (Kumho Tire Co., Ltd, v. Carmichael, 526 U.S. 137 (1999) allows the court to consider any reasonable factor, and courts are constantly rendering decisions that interpret and add to the factors.

Finally, Kumho's holding that the trial judge must determine what factors will be used to evaluate the reliability of expert testimony suggests a tactic not often used. The expert should be asked what factors in his purported field of expertise are used to assess the reliability of opinions such as they are giving. Experts rarely are prepared for this line of questioning and often have difficulty formulating an answer. A lack of knowledge concerning factors to assess the reliability of the precise opinions he is rendering tends to indicate that the testimony is unreliable.

Daubert Tactics ' Briefing

Counsel should endeavor to keep their briefing of a Daubert motion as simple and concise as possible. The record concerning each of the potential Daubert factors should be carefully reviewed and the evidence marshaled to show how the expert's methodology fails to satisfy particular factors. The briefing should then set out why the record shows particular factors were not met and argue that based on those factors the opinion is irrelevant and unreliable.

Several arguments should be considered in addition to showing failure on particular reliability or relevance factors. Based on General Electric Co. v. Joiner, 522 U.S.136 (1997) and the third element of Rule 702, an argument should be considered that the conclusions reached are simply too remote from the data upon which the expert relies. Likewise, the Rand study found that judges are increasingly considering the clarity and coherence of an expert's explanation of his theory, methods, and procedures. This suggests that arguments generally addressing the overall completeness and competence of the expert's opinion should be considered. Finally, an argument under Rule 403, Fed. R. Evid., should be considered. An expert's opinion, although marginally reliable, may have such de minimis probative value that its potential for confusing the jury or unfair prejudice requires its exclusion.

Daubert Tactics – Hearings

An important decision is whether to request a hearing on the motion. District courts have broad discretion in determining whether they will conduct such a hearing. Generally it is advisable simply to rely on the record if counsel believes that it is sufficient to disqualify the expert. A hearing may only give the expert an opportunity to fortify his testimony. Nevertheless, in some instances, a hearing will be necessary because the particular court will be disinclined to grant a dispositive motion without hearing testimony or the record may be incomplete concerning inadequacies of the expert's testimony.

Conclusion

Implementation of an effective Daubert strategy in most product liability cases is difficult, tedious, and time-consuming. Nevertheless, the rewards that can be reaped are substantial. Most product liability cases turn on expert evidence. Thus, counsel should assemble a record that will support exclusion of the opposing expert based on the various Daubert factors and determine their strategy as soon as possible. If the record is sufficiently strong, a motion should be filed that concisely sets forth the argument for exclusion.

Robert O. Lesley is a partner in the Kansas City, MO, office of Sonnenschein Nath & Rosenthal. He specializes in the defense of products liability cases and other complex litigation. Phone: 816-460-2556.

This is the second of a two-part article. Part one appeared in last month's issue.

The first part of this two-part article explored the development of the standards for admission of expert testimony under Daubert, and discussed strategies and tactics for dealing with them. The conclusion addresses tactics for use while deposing an expert, briefing a Daubert motion, and conducting a hearing on the motion.

Daubert Tactics ' The Expert's Deposition

The initial point of deposition attack should be the expert's qualifications. Daubert stated that the court must determine whether the proffered testimony “fits” the facts of the case. The determination of “fit” is, in essence, a relevance inquiry that requires a showing of more than bare relevance. See In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 745 (3d Cir. 1994). The qualifications of the expert should be explored to determine whether the body of knowledge in which they claim expertise fits the case. For example, a court disqualified a mechanical engineering expert in an electrical shock case because he was not an electrical engineer. See Trumps v. Toastmaster Inc. , 969 F. Supp. 247, 252 (S.D.N.Y. 1997).

The expert should be questioned concerning all of the data upon which he or she relies, with the goal of showing that some relevant data have not been included, or some data are unreliable. Failure to consider all relevant data in forming an opinion is a basis for finding them unreliable. See United Phosphorus, Ltd. v. Midland Fumigant, Inc. , 173 F.R.D. 675, 683-84 (D. Kan. 1997). The requirement of Rule 703, Fed. R. Evid., that supporting data be of the type reasonably relied upon by other experts in the field, should also be kept in mind. If an expert relies on unreliable data, he or she should be thoroughly questioned on whether other experts in the field rely on such data, and their basis for such reliance. Even if other experts rely on the data, the reasonableness of the reliance can be challenged. For example, reliance on Consumer Product Epidemiological Investigation Reports, which are reviewed by experts in many cases, has been successfully challenged because they contain unreliable hearsay statements. See Knotts v. Black & Decker, Inc. , 204 F. Supp. 2d 1029, 1041 (N.D. Ohio 2002). The expert should be examined concerning all documents that contain the data upon which he or she relies, and the documents should be produced if they have not been up to that point. Even if an expert makes a facial assertion that the opinion is based on reliable data, further examination may reveal otherwise. For example, the expert may claim to base his or her opinion on testing. Such testing may have been conducted for other cases in which the expert was advocating a similar position, or records of the testing may not exist.

All assumptions made by the expert should be scrutinized. A careful examination of his or her opinion will often reveal totally unsupported assumptions. As an example, experts in fire cases many times assume that a product can ignite a fire without knowing the temperature the product can generate, or the ignition temperatures of surrounding combustibles. Similar assumptions are made in many other types of cases. Unwarranted assumptions are an accepted basis under Daubert for disqualifying an expert. See Boucher v. United States Suzuki Motor Corp., 73 F.3d 18, 21 (2d Cir. 1996).

The precise methodology used by the expert to formulate his or her opinion should be established. In many cases, the methodology will consist of no more than an inspection of the product and an application of alleged scientific or technical principles to knowledge gained from the inspection. In cases where the product is alleged to have caused a disease, experts commonly review the plaintiff's medical records and apply assumptions based on epidemiological studies to those data. If the expert's methodology was only reviewing a product or data, and applying alleged principles, he or she should be required to state that fact. A concise statement of the methodology by the expert will assist the court in assessing its reliability.

Once the methodology is identified, the following five factors identified in Daubert are the starting point for assessing its reliability:

• whether a theory or technique has been or can be tested;
• whether it has been subjected to peer review and publication;
• whether there are standards for its application;
• whether it has a known or potential error rate; and
• whether it is generally accepted within a relevant expert community.

Not all factors may apply to the testimony of a particular expert. Counsel should assess which factors reasonably may be applied. Because expert testimony concerning liability issues in products cases is generally scientific or technical, all of the Daubert factors usually will be a reasonable source of deposition questions.

Some courts have stated that testing or testability is the most important Daubert factor in a reliability inquiry. See Bradley v. Brown , 42 F.3d 434, 438 (7th Cir. 1994). The expert should be required to describe thoroughly all testing conducted to substantiate his or her conclusions. The expert should then be questioned concerning any other relevant testing he or she can imagine that could be conducted. If he or she can identify other available tests, the attorney should ask why the expert has not conducted them. If the expert cannot identify a way to test, he or she should be required to state that the stated opinion is not testable.

Even when testing is conducted, it may not “fit” the facts of the case. The expert should be challenged to explain why the testing shows anything relevant concerning the case. In a recent case, a purported expert tried to prove that food could jam a product's mechanism by himself jamming the mechanism with a metal object. The “testing” obviously did not fit the case facts, because a metal object in no way simulated the food that allegedly jammed the product.

Continuing the Daubert factor questioning, the expert should be asked whether his or her methodology has been peer-reviewed and published, and what standards exist for its application. If the expert has only inspected a product and formed his or her own opinion, it is unlikely that he or she will be able to identify any publications or standards to support that methodology. The opinion may then be attacked on the grounds that it is based on an unverifiable methodology and is really just result-oriented advocacy. Likewise, the expert should be asked to identify peer-review, publishing, and standards for the underlying principles and knowledge that he or she is purporting to apply to the facts of the case.

Questions about the error rate of the methodology can produce particularly interesting answers. An expert should be asked to state how often the methodology produces incorrect results. Experts are often not prepared to answer questions concerning error rate, but a known error rate is essential to assessing reliability. If an expert testifies that he or she has never erred, an error rate cannot be calculated, and the expert's credibility may be diminished.

The expert should be questioned about the final Daubert factor, whether his or her methodology is generally accepted in the field. If the methodology is accepted, according to the expert, the basis for that assertion should be explored. The expert should be required specifically to identify other authorities who use the methodology so that the extent of acceptance can be determined.

The inquiry should not stop with the original five Daubert factors. Case law reveals many other factors that may be considered. For example, questions concerning potential alternate causes of the accident or illness should be asked in many cases. Failure to account for alternate causes can render a methodology unreliable. See Claar v. Burlington N.R.R. Co. , 29 F.3d 499, 502 (9th Cir. 1994). The precise standard for elimination of a potential cause should also be stated. The uniform application of the standard will also often lead to the elimination of the thing the expert identified as a cause. The expert should be asked whether he conducted the work in the same manner as his non-litigation work. A failure to do so indicates unreliability. Sheehan v. Daily Racing Form, Inc., 104 F.3d 940, 942 (7th Cir.), cert. denied , 521 U.S. 1104 (1997). Likewise, reliance on research conducted solely for litigation also indicates unreliability. See Daubert v. Merrill Dow Pharmaceuticals , Inc., 43 F.3d 1311, 1317 (9th Cir.), on remand from, Daubert , 509 U.S. 579 (1995). The inquiry should not end with the factors listed here. Kumho's flexible inquiry ( Kumho Tire Co., Ltd, v. Carmichael , 526 U.S. 137 (1999) allows the court to consider any reasonable factor, and courts are constantly rendering decisions that interpret and add to the factors.

Finally, Kumho's holding that the trial judge must determine what factors will be used to evaluate the reliability of expert testimony suggests a tactic not often used. The expert should be asked what factors in his purported field of expertise are used to assess the reliability of opinions such as they are giving. Experts rarely are prepared for this line of questioning and often have difficulty formulating an answer. A lack of knowledge concerning factors to assess the reliability of the precise opinions he is rendering tends to indicate that the testimony is unreliable.

Daubert Tactics ' Briefing

Counsel should endeavor to keep their briefing of a Daubert motion as simple and concise as possible. The record concerning each of the potential Daubert factors should be carefully reviewed and the evidence marshaled to show how the expert's methodology fails to satisfy particular factors. The briefing should then set out why the record shows particular factors were not met and argue that based on those factors the opinion is irrelevant and unreliable.

Several arguments should be considered in addition to showing failure on particular reliability or relevance factors. Based on General Electric Co. v. Joiner, 522 U.S.136 (1997) and the third element of Rule 702, an argument should be considered that the conclusions reached are simply too remote from the data upon which the expert relies. Likewise, the Rand study found that judges are increasingly considering the clarity and coherence of an expert's explanation of his theory, methods, and procedures. This suggests that arguments generally addressing the overall completeness and competence of the expert's opinion should be considered. Finally, an argument under Rule 403, Fed. R. Evid., should be considered. An expert's opinion, although marginally reliable, may have such de minimis probative value that its potential for confusing the jury or unfair prejudice requires its exclusion.

Daubert Tactics – Hearings

An important decision is whether to request a hearing on the motion. District courts have broad discretion in determining whether they will conduct such a hearing. Generally it is advisable simply to rely on the record if counsel believes that it is sufficient to disqualify the expert. A hearing may only give the expert an opportunity to fortify his testimony. Nevertheless, in some instances, a hearing will be necessary because the particular court will be disinclined to grant a dispositive motion without hearing testimony or the record may be incomplete concerning inadequacies of the expert's testimony.

Conclusion

Implementation of an effective Daubert strategy in most product liability cases is difficult, tedious, and time-consuming. Nevertheless, the rewards that can be reaped are substantial. Most product liability cases turn on expert evidence. Thus, counsel should assemble a record that will support exclusion of the opposing expert based on the various Daubert factors and determine their strategy as soon as possible. If the record is sufficiently strong, a motion should be filed that concisely sets forth the argument for exclusion.

Robert O. Lesley is a partner in the Kansas City, MO, office of Sonnenschein Nath & Rosenthal. He specializes in the defense of products liability cases and other complex litigation. Phone: 816-460-2556.