Nor do they know the vocabulary that is used to present and explain the results, or they know it only in part. Lay people cannot perform the relevant tests. The naked eye cannot see these properties. Blood analysis, simply put, is the laboratory examination of a sample of blood used to obtain information about its physical and chemical properties. Footnote 3 Consider, as a rather familiar example, blood or tissue analysis. Expert testimony provides indeed a peculiar kind of evidence, since (i) it employs expert signs, (ii) the non-expert recipients can hardly understand it, and (iii) it is not just transmission of information, but also production of information. When expert witnesses provide them, they sound like Mandarin to someone who is at ease with Begriffsjurisprudenz (the judge) or with football and pizza (the juror). They do not know what those signs refer to.

Take “polychlorinated biphenyls”, or other special signs used in chemistry. Expert signs are often unintelligible to non-experts. Footnote 2 But, as far as I know, there is little analysis of the semiotic aspects of expert testimony and expert evidence, and little consideration of the impact that legal burdens have on expert evidence issues. What is the point of providing expert evidence if the factfinders cannot appreciate its details or do not even understand it? There is a vast and growing literature on this subject and the problem highlighted. The subjects vary a lot, from chemistry and botany to psychiatry and economics, from the causes of pollution to the causes of schizophrenia, from medical malpractice to antitrust cases, including technical issues and supposedly technical disciplines such as tire failure analysis.Īll of that comes with a concern that is now a refrain: How can legal factfinders adjudicate disputes whose content turns out to be expert, if they lack the relevant expertise? Judges are mainly trained in law jurors are supposed to rely on standard knowledge and common sense. Examples of this sort are legion, for contemporary legal practice shows that a remarkable and increasing amount of legal controversies depend on the answers to expert questions. Those cases are mostly known for legal reasons, as it will be clear, and the examples have nothing special. Footnote 1 They are taken from well-known cases that will be considered below. Have you ever discussed a “reanalysis” of epidemiological studies to the purpose of establishing whether a given substance is a human teratogen? Do you know what polychlorinated biphenyls are? Do you know what experts mean by “beads” when talking about a tire? What about a “bead seat” in the same context?Īctually, those are examples of expert questions for legal factfinders.

Expert testimony definition literature