Online research in philosophy

Using the controversy over the MMR vaccine, I consider the reasons why non-experts should defer to experts, and I sketch a model for understanding cases where they fail to defer. I first suggest that an intuitively plausible model of the expert/non-expert relationship is complicated by shifting epistemic standards. One possible moderate response to this challenge, based on a more complex notion of non-experts' relationship with experts, seems unappealing as an account of the MMR controversy. A more radical suggestion is that non-experts might have a political reason to defer to experts, when not doing so will involve ‘epistemological free-riding’. I investigate the implications.

This Article, published in a symposium issue focusing on science and expertise, traces the early reception of the modern expert witness. It describes in some detail the widespread frustrations with expert witnesses in court in the closing decades of the nineteenth century, focusing in particular on the two most vociferous critiques: that experts too often became partisans, mere mouthpieces for the party that hired them; and that expert testimony was so frequently contradictory that it confused and perplexed, rather than enlightened, the lay jurors who heard it. The Article argues that these criticisms can only be properly understood by recognizing two important aspects of how expert evidence was being wielded and understood in this period. First, it is important to recognize that even amidst the rampant complaints by the bench, bar, and experts themselves, about the content and methods of expert testimony, the actual use of expert evidence was simultaneously increasing. Second, I argue that a key source of the dissatisfaction with expert testimony was a disjunction between a set of idealized expectations for scientific evidence and the practical realities of its use in the courtroom. It was precisely because of what science was thought to be able to offer to the process of legal decisionmaking, that the spectacle of warring experts provoked such frustration and anger. Science ought to have been able to offer proof more objective, more certain, and more neutral than that of the lay eyewitness, or so believed scientists and legal commentators alike. When it failed to do so, this failure was frequently attributed to partisan excess or the problems of adversarialism, rather than recognized as being, at least in significant part, the result of unrealistic expectations for science itself. In the conclusion, I suggest that this idealized conception of science lingers with us today as well, and continues to influence how we understand and critique expert evidence in court.

As Hammond has argued, traditional explanations for disagreement among experts (incompetence, venality, and ideology) are inadequate. The character and fallibilities of the human judgement process itself lead to persistent disagreements even among competent, honest, and disinterested experts. Social Judgement Theory provides powerful methods for analysing such judgementally based disagreements when the experts' judgement processes can be represented by additive models involving the same cues. However, the validity and usefulness of such representations depend on several conditions: (a) experts must agree on a problem definition, (b) experts must have access to the same information, and (c) experts must use the same organising principles. When these conditions are not met, methods for diagnosing and treating disagreement are poorly understood. As a start towards developing such an understanding, sources of expert disagreement are discussed and categorised.

This paper argues that the problem of expertise calls for a rapprochement between social epistemology and argumentation theory. Social epistemology has tended to emphasise the role of expert testimony, neglecting the argumentative function of appeals to expert opinion by non-experts. The first half of the paper discusses parallels and contrasts between the two cases of direct expert testimony and appeals to expert opinion by our epistemic peers, respectively. Importantly, appeals to expert opinion need to be advertised as such, if they are to sway an epistemic peer. The second half of the paper sketches a theoretical framework for thinking about assessments of expertise in a unified way, via a ‘default and challenge’ model that emphasises the need for a version of conversational scorekeeping. It is through such scorekeeping that interlocutors can track and coordinate their differences in epistemic outlook. The paper concludes with a genealogical perspective on the function of (attributions of) expertise: acceptance of another’s appeal to expert opinion may be construed as tacit agreement that inquiry, for now, has been taken far enough.

This article discusses the conditions under which the use of expert knowledge may provide an adequate response to public concerns about high-tech, late modern risks. Scientific risk estimation has more than once led to expert controversies. When these controversies occur, the public at large – as a media audience – faces a paradoxical situation: on the one hand it must rely on the expertise of scientists as represented in the mass media, but on the other it is confused by competing expert claims in the absence of any clear-cut standard to judge these claims. The question then arises, what expertise can the public trust? I argue that expert controversies cannot be settled by appealing to neutral, impartial expertise, because each use of expert knowledge in applied contexts is inextricably bound up with normative and evaluative assumptions. This value-laden nature of expert contributions, however, does not necessarily force us to adopt a relativist conception of expert knowledge. Nor does it imply active involvement of ordinary citizens in scientific risk estimation – as some authors seem to suggest. The value-laden, or partisan, nature of expert statements rather requires an unbiased process of expert dispute in which experts and counter-experts can participate. Moreover, instead of being a reason for discrediting expert contributions, experts'' commitment may enhance public trustworthiness because it enlarges the scope of perspectives taken into account, to include public concerns. Experts who share the same worries as (some of) the public could be expected to voice these worries at the level of expert dispute. Thus, a broadly shaped expert dispute, that is accessible to both proponents and opponents, is a prerequisite for public trust.

The past two decades have seen a dramatic growth in the use of statisticians and economists for the presentation of expert testimony in legal proceedings. In this paper, we describe a hypothetical case modeled on real ones and involving statistical testimony regarding the causal effect of lead on lowering the IQs of children who ingest lead paint chips. The data we use come from a well-known pioneering study on the topic and the analyses we describe as the expert testimony are similar to ones that can be found in major scientific journals. The battle of the experts in this hypothetical case resembles that which many encounter as expert witnesses. The paper concludes with some observations and advice.

We examined the dilemmas posed by the involvement of expert witnesses in court cases and the institutional constraints on the ethics of expert testimony. The causes for the incorporation of bad science into legal decisions, potential solutions to this dilemma, and the limitations of these solutions are considered. We concluded that law, science, and experts must respond to the problems posed by expert witnessing.

A recent Supreme Court decision, Kumho Tire Co., Ltd. v. Carmichael (March 23, 1999), may have substantial impact on psychological expert testimony. Previous criteria for admissibility of scientific expert testimony now apply broadly to expert testimony, not just testimony narrowly grounded in scientific evidence. Judges will determine the relevance and reliability of all expert testimony, including that based on clinical experience or training. Admissible testimony will either satisfy the criteria established in Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) or meet similarly rigorous standards judged appropriate to the particular field involved. Because psychological testimony has varied in its evidentiary basis, sometimes relying on science and otherwise on clinical training or experience, court decisions will gradually determine the precedent for its admissibility. We also discuss long-term consequences for the credibility of psychological expert testimony and the relation between psychology and law.

This article draws upon the epistemology of testimony to analyse recent English case law on expert evidence. It argues that the courts are implicitly committed to an internalist epistemology and an inferentialist view of testimony, and draws a distinction between testimony which is treated as authoritative (where the fact-finder accepts the inferences drawn by the expert without attempting to assess their validity) and that which is treated as merely persuasive.