Michael J. Saks

The Daubert/Kumho Implications of Observer Effects in Forensic Science: Hidden Problems of Expectation and Suggestion

Introduction: The Requirements of Kumho Tire Co. v. Carmichael ........... 3 I. Observer Effects .................................................................... 6 A. Evolution of the Awareness of Observer Effects ....................... 6 B. What This Article Is Not About (Honesty and Observer Effects) ...................................................................................... 10 C. The Psychology of Observer Effects ......................................... 12

Children’s Competence to Consent

The question of children’s competence to give or refuse consent1 is of largely recent origin (see Chapter 9). Until the mid-sixties it was not clear that children were “persons” within the meaning of the Fourteenth Amendment, which makes the Bill of Rights applicable to the states. Although there were several early-twentieth-century “children’s rights” cases decided by the United States Supreme Court,2 each of these could be construed as a vindication of parents’ liberty interest in childrearing as they saw fit (Melton, 1982). In none of the early cases was there a clear indication of minors’ possessing constitutionally protected fundamental liberties independent of their parents. Children were perceived as properly dependent upon their parents who possessed a “right of control” over them.3 Even though parents’ rights in this regard are limited by the fact that they are not “free … to make martyrs of their children,’4 this restriction emanated from the state’s interest in the socialization of children.5 Indeed, the Supreme Court had held that it “would hardly seem open to question” that the state could impinge on basic freedoms of minors (e.g., freedom of religion) in ways that would be clearly unconstitutional if the same restrictions were placed on adults.6 Given clear indications that both parents and the state as parens patriae 7 could exercise control over minors (see Chapter 9 for additional discussion), the question of the limits of children’s actual competence to make personal decisions was moot.

The Testimony of Forensic Identification Science: What Expert Witnesses Say and What Factfinders Hear

This research examined how variations in the presentation of forensic science information affect factfinders’ judgments in a trial. Participants read a summary of a murder case, the critical testimony being the results of a microscopic hair comparison given by a forensic expert. Across two experiments we manipulated how the expert expressed his results, whether he gave an explicit conclusion concerning identity of the hair, and whether the limitations of forensic science were expressed during trial. Qualitative testimony was more damaging to the defense than quantitative testimony, conclusion testimony increased the defendant’s culpability ratings when findings were presented quantitatively, and expressing limitations of forensic science had no appreciable effect. Results are discussed in terms of factfinders’ interpretation of forensic identification evidence.

A Meta-Analysis of the Effects of Jury Size

In a series of opinions in the 1970s, the U.S. Supreme Court concluded that juries smaller than 12 persons would be constitutional if they performed no differently than traditional 12-person juries. In a meta-analysis, we examined the effects of jury size on the criteria the court specified as the basis for making such comparisons. A search for all relevant empirical studies identified 17 that examined differences between 6- and 12-member juries. The total sample for the 17 studies was 2,061 juries involving some 15,000 individual jurors. Among other findings, it appears that larger juries are more likely than smaller juries to contain members of minority groups, deliberate longer, hang more often, and possibly recall trial testimony more accurately.

Reducing Variability in Civil Jury Awards

The purpose of the present study was to test several procedures that could be adopted for reducing unwanted variability in civil damage awards. Four methods for providing guidance to jurors (and judges) about the distribution of awards in comparable cases were compared to each other, to a no-guidance control, and to the capping of awards at a specified maximum, which has been the most commonly legislated “solution.” The findings of this study suggest several alternative solutions that are better able than caps to solve the problem of unwanted variability in awards.

Letter to the Editor- Context Management Toolbox: A Linear Sequential Unmasking (LSU) Approach for Minimizing Cognitive Bias in Forensic Decision Making.

J Forensic Sci, July 2015, Vol. 60, No. 4 doi: 10.1111/1556-4029.12805 Available online at: onlinelibrary.wiley.com Letter to the Editor— Context Management Toolbox: A Linear Sequential Unmasking (LSU) Approach for Minimizing Cognitive Bias in Forensic Decision Making Sir, The 2009 NAS report (1) criticized forensic scientists for making insufficient efforts to reduce their vulnerability to cogni- tive and contextual bias. Over the past few years, however, the field has begun to take steps to address this issue. There have been major workshops on cognitive bias, and the Organization of Scientific Area Committees (OSAC), 1 as well as the National Commission on Forensic Science, have created committees on Human Factors that are specifically charged with examining this issue. 2 A number of tools and methods for minimizing bias are under consideration. Some of these tools have already been imple- mented in a few forensic laboratories. In general, these tools are designed to protect and enhance the independence of mind of forensic examiners, particularly those who rely on subjective judgment to make their decisions. Several types of contextual information are of concern, as illus- trated in Fig. 1. We organize them into a taxonomy of five levels (based on a four-level taxonomy suggested by Stoel et al. [2]). The five-level taxonomy differentiates task-irrelevant information that may be conveyed to an analyst by the trace evidence itself (Level 1), the reference samples (Level 2), the case information (Level 3), examiners’ base rate expectations that arise from their experience (e.g., when the examiner expects a particular result— Level 4), and organizational and cultural factors (Level 5). A variety of tools are available for addressing cognitive bias. Different tools are useful for managing exposure to each level of task-irrelevant information. For example, case managers (3,4) is a straightforward tool for dealing with bias from case informa- tion (Level 3). In general, these procedures are designed to pre- vent contextual bias by protecting the examiner from exposure to task-irrelevant information. However, it is important to note that some types of information, while potentially biasing, may also be task relevant (5). These types of biasing information are more difficult to deal with. For example, in some instances, evidence that analysts must examine to perform their duties may contain information that is potentially biasing. This can pertain to cases in which Level 1 information, the trace evidence being evaluated, contains contextual informa- tion (e.g., blood spatter patterns that contain information about the nature of the crime, or handwriting and voice samples in which the meaning of the words is potentially biasing). Reference samples are another example of relevant material that is also potentially biasing (Level 2). These samples are clearly relevant because the analyst must compare them to trace evidence samples to determine whether they are similar enough to conclude that they come from the same source. But it is pos- sible that an analyst’s interpretation of the trace evidence might inadvertently be influenced by knowing the characteristics of the See: http://www.nist.gov/forensics/osac/hfc.cfm. The authors of this letter are comprised primarily from members of the OSAC Human Factors Committee, the Human Factors Subcommittee of the National Commission on Forensic Science, and authors of the original Sequential Unmasking.

Expert witnesses, nonexpert witnesses, and nonwitness experts

The role and responsibilities of the expert winness is a controversial subject. This article emphasizes the legal rules (of evidence and procedure) governing the expert and the policy grounds on which they rest. As the laws policies for the use of expertise shift from stage as stage as litigation progresses, or differ between categories of legal cases (criminal vs. civil), or with a partys use of an expert (from being a nonwitness consultant to an expert witness at trial), the law expects the role of the expert to be reshaped accordingly. On some important issues, the law sends contradictory messages: What its formal rules announce is at war with its structure and practices. And these, in turn, sometimes are in tension with the demands of the experts professional ethical codes. On other matters of importance to experts, the law is silent, because the rules were motivated by a need to control the behavior of parties and lawyers, not experts. The result of all this is to present those who would be conscientious expert witnesses with a need to resolve nearly impossible role conflicts and ethical dilemmas.

DECISIONMAKING ABOUT GENERAL DAMAGES: A COMPARISON OF JURORS, JUDGES, AND LAWYERS

The research reported in this Article investigates jurors’ perceptions of injury seriousness and awards of general damages, and compares them to judges’ and lawyers’ responses to the same injuries. We developed regression models for each group of decision makers to determine which attributes of the injuries had what degree of impact on injury severity judgments and on awards. The models also examined how differences in geography, demography, and experiences affected decisions. The models showed a remarkable degree of similarity among the decision-making groups when evaluating the severity of injuries. That is, jurors, judges, and lawyers largely relied on the same injury attributes in similar ways and gave them similar relative weight. When it came to translating injury perceptions into monetary awards, however, more differences among the groups appeared, and the predictive power of the models declined. The findings suggest that the differences between jurors’ awards and those of the other groups do not reflect fundamental differences in decision making, but rather a loss of consistency in translating perceptions of injury severity into damages. That loss of consistency likely can be attributed to the fact that jurors lack the frame of reference created by other cases that is readily available to judges and lawyers. The article concludes with a discussion of the policy implications of the findings.

Prevalence and Impact of Ethical Problems in Forensic Science

The prevalence of ethical problems in the forensic sciences is difficult to discover because of the limited sources of this information. A clear understanding of ethical violations is essential to establish the extent to which justice is hindered by unethical conduct among forensic scientists and then to improve the ethical state of the profession by addressing these specific problems. Seven major classes of evidence of ethical conduct and examples of each are examined: proficiency testing studies, self-report surveys and focus groups, complaints to forensic science associations, court cases, content analysis of ethical codes, anecdotal data (news reports, the professional literature, and case studies), and circumstantial evidence. Three main categories of ethical problems emerged from the data: problems of competency, individual misbehavior, and problems of practicing science in an adversary system. There is a need for more studies and various data collections to improve understanding of ethical problems in the forensic sciences and to seek to ameliorate them.

The application of signal detection theory to decision-making in forensic science.

Signal Detection Theory (SDT) has come to be used in a wide variety of fields where noise and imperfect signals present challenges to the task of separating hits and correct rejections from misses and false alarms. The application of SDT helps illuminate and improve the quality of decision-making in those fields in a number of ways. The present article is designed to make SDT more accessible to forensic scientists by: (a) explaining what SDT is and how it works, (b) explicating the potential usefulness of SDT to forensic science, (c) illustrating SDT analysis using forensic science data, and (d) suggesting ways to gain the benefits of SDT analyses in the course of carrying out existing programs of quality assessment and other research on forensic science examinations.