By Chris Wullum
The Reliable Foundation Test
Daubert v. Merrell Dow Pharmaceutical Inc., 509 U.S. 579 (1993) is a well-known and often cited opinion issued from the United States Supreme Court concerning the rules and factors applicable to admitting expert scientific evidence in federal trial courts in the United States. The case introduced what is known as the “reliable foundation” test that overturned the previously long-standing “general acceptance” test pronounced in Frye v. United States, 293 F. 1013 (D.C. Cir 1923).
In Daubert, the U.S. Supreme Court confirmed that the trial judge has a “gatekeeper” role in determining the reliability and relevance of expert testimony. Four primary factors were identified to assess the evidential reliability of a proposed expert’s evidence:
- Whether the expert’s technique or theory can be or has been tested;
- Whether the technique or theory has withstood peer review and publication;
- Whether there is a known or potential rate of error or the existence of standards to test the application of the technique or theory; and
- Whether the technique or theory has been generally accepted by the relevant scientific community.
The Supreme Court further cautioned that this was not a definitive checklist of factors and that it was to be considered flexible wherein each factor may not necessarily or exclusively apply to all expert evidence sought to be introduced in a case. Under this new approach, the Court appeared to be encouraging a more liberal approach of admitting expert testimony while then relying on the importance of subjecting expert witnesses to vigorous cross-examination on the weight and substance of the opinion. In contrast, in the earlier Frye decision of the U.S. Supreme Court, the focus for admissibility was solely on whether the scientific technique or theory upon which the opinion is based is “generally accepted” as reliable in the relevant scientific community.
The Daubert decision and the factors discussed by the Court have evolved into the frequent use of “Daubert motions” whenever there are challenges to the admissibility of expert evidence at a federal trial, particularly with novel science and techniques. For instance, in Daubert, the expert evidence concerned the introduction of epidemiological studies to demonstrate whether a particular anti-nausea drug was capable or not of causing birth defects.
In a subsequent opinion of the U.S. Supreme Court, Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), the Court further determined that the Daubert standard even applied to expert testimony that is not scientific in nature, stating that the standard, in accordance with the applicable U.S. statute, applies to witnesses that have non-scientific technical or other specialized knowledge.
The Canadian experience with Daubert
In Canada, the principles from Daubert and its “reliable foundation” test and the trial judge acting as a “gatekeeper”, have found their way into several Canadian decisions on expert evidence. The Supreme Court of Canada has typically discussed the rules for admitting novel expert evidence in the criminal law context but the principles from these decisions can still be applied to other situations in which expert evidence is sought to be introduced at trial, and therefore have important application in civil litigation cases as well.
R. v. Mohan
The Supreme Court of Canada set out a principled approach for trial courts to follow when assessing the admissibility of expert evidence. In 1994, in the now foundational decision of R. v. Mohan,  2 S.C.R. 9, the Supreme Court of Canada identified the following four criteria for considering the admission of expert evidence:
- The evidence is relevant to some issue in the case;
- The evidence is necessary to assist the trier of fact;
- The evidence does not contravene an exclusionary rule; and
- The witness is a properly qualified expert.
These four principles have become the foundation in Canada for any analysis of admissibility of expert evidence, and similar to Daubert in the U.S., forms the basis for trial voir dires whenever expert evidence is challenged for exclusion.
In a subsequent Supreme Court of Canada decision of R. v. J.-L.J., 2000 SCC 51, the Court went further in its consideration of how to evaluate the reliability of novel science or techniques sought to be admitted at trial. The Court expressly recognized that Canada was moving in parallel with the “reliable foundation” principles set out in Daubert and confirmed the four Daubert factors could be applied in consideration of novel science and techniques under Canadian law. The Court sought to emphasize that novel science or techniques must meet a basic level of reliability that would have to be reviewed in each case.
The Daubert principles were also discussed by the Ontario Court of Appeal in R. v. Abbey, 2009 ONCA 624 where in the context of a criminal case the Court was considering the admission of non-scientific evidence from a sociology expert on tattoos and gang culture. The Court in Abbey stated that a strict application of the four Daubert factors was not appropriate for assessing the reliability of the evidence sought to be introduced in that case and that a flexible and modified approach would be required in cases where the expert evidence was not purely scientific in nature. In respect of the expert in Abbey, the opinion was not based upon “scientific theory” but rather research and experience which permitted the expert to have developed a specialized knowledge about gang culture and symbology. So while an assessment of the reliability of the proposed evidence is still essential to its admission, the factors for assessing it may need to be adapted to the particular evidence at issue. The Court of Appeal in Abbey offered the following factors as suggestions for assessing reliability in such non-scientific situations:
– To what extent is the field in which the opinion is offered a recognized discipline, profession or area of specialized training?
– To what extent is the work within that field subject to quality assurance measures and appropriate independent review by others in the field?
– What are the particular expert’s qualifications within that discipline, profession or area of specialized training?
– To the extent that the opinion rests on data accumulated through various means such as interviews, is the data accurately recorded, stored and available?
– To what extent are the reasoning processes underlying the opinion and the methods used to gather the relevant information clearly explained by the witness and susceptible to critical examination by a jury?
– To what extent has the expert arrived at his or her opinion using methodologies accepted by those working in the particular field in which the opinion is advanced?
– To what extent do the accepted methodologies promote and enhance the reliability of the information gathered and relied on by the expert?
– To what extent has the witness, in advancing the opinion, honoured the boundaries and limits of the discipline from which his or her expertise arises?
– To what extent is the proffered opinion based on data and other information gathered independently of the specific case or, more broadly, the litigation process?
R. v. Abbey also discussed a two-step approach to determining admissibility of expert evidence under the Mohan principles. The first step requires a demonstration that the proposed evidence meets the four threshold requirements of admissibility set out in Mohan, and the second step then involves the trial judge acting as a “gatekeeper” to perform a discretionary cost-benefit analysis as to whether the proposed evidence is sufficiently beneficial to the trial process when assessed against any potential harm from its admission (the probative value vs. its prejudicial effect). This is a similar “gatekeeper” function of the trial judge as has been discussed in Daubert and other U.S. decisions.
This two-step approach was formally adopted by the Supreme Court of Canada in White Burgess Langille Inman v. Abbott and Haliburton, 2015 SCC 23. Ultimately, when assessing the reliability of proffered expert evidence in Canada, the focus of the analysis will usually be in the second step “gatekeeper” stage, but may also come into play in assessing legal relevance as a first factor from Mohan.
Summary Since Mohan, the “reliable foundation” principles from Daubert have found favour in Canadian decisions when considering the threshold issue of reliability of expert evidence at the admissibility stage. In cases where novel science or technique is sought to be introduced, the trial judge will typically apply a stricter level of scrutiny than when the theories or techniques have more general acceptance. Having said that, novelty of a theory or technique is not determinative of admissibility and general acceptance is but one factor for consideration. Each case or situation will require its own unique analysis with guidance from the principles provided in Daubert, Mohan, and Abbey.