The effectiveness of opposing expert witnesses for educating jurors about unreliable expert evidence.

Abstract

We tested whether an opposing expert is an effective method of educating jurors about scientific validity by manipulating the methodological quality of defense expert testimony and the type of opposing prosecution expert testimony (none, standard, addresses the other expert's methodology) within the context of a written trial transcript. The presence of opposing expert testimony caused jurors to be skeptical of all expert testimony rather than sensitizing them to flaws in the other expert's testimony. Jurors rendered more guilty verdicts when they heard opposing expert testimony than when opposing expert testimony was absent, regardless of whether the opposing testimony addressed the methodology of the original expert or the validity of the original expert's testimony. Thus, contrary to the assumptions in the Supreme Court's decision in Daubert, opposing expert testimony may not be an effective safeguard against junk science in the courtroom.

Comparison of plaintiff and defendant expert witness qualification in malpractice litigation in neurological surgery

“…18,20,25,26,44 A recent analysis found that proceedings featuring opposing medical expert testimony caused jurors to be skeptical of all testimony rather than to select a side they found to be more credible. 30 Medical malpractice litigation and subsequent calls for tort reform have increased appreciably over the past 3 decades, with analyses estimating additional costs to our health care system as high as $10 billion annually from litigations. 1,32,62,63 Given that neurological surgery has the highest proportion of physicians facing a malpractice claim each year (19.1%), a large proportion of these malpractice costs can be attributed to litigation in this field.…”

A qualitative analysis of mock jurors' deliberations of linkage analysis evidence

“…Levett and Kovera (2008) found that when mock jurors were presented with opposing expert evidence they became sceptical of all expert evidence. Similarly, Brekke and Borgida (1988) found that when two confl icting expert testimonies were given in simulated rape trials, mock jurors rejected both and relied on their own theories.…”

Unloading the hired gun: Inoculation effects in expert witness testimony

“…This project demonstrated for the first time that a single expert, testifying without being opposed by an expert retained by the other side, can still be viewed as a hired gun. Previous studies had only examined hired gun experts in the context of two competing experts (Cooper & Neuhaus, 2000;Levett & Kovera, 2008). These research paradigms frequently compared an expert who was highly paid to one who was not, or an expert with impressive credentials to one with less impressive credentials.…”

“…Interestingly, this finding occurred with no mention of the expert's pay or frequency of testimony. Levett and Kovera (2008) previously found that the mere presence of an opposing expert caused mock jurors to question the validity of all expert testimony. This skepticism effect was found regardless of the content of the opposing expert's testimony.…”

“…Levett and Kovera (2008) showed that the mere presence of an opposing witness calls the original witness's findings into question. The current project provides a more pure test of whether high pay and frequent testimony alone are enough to trigger the hired gun schema.…”