A sequential sampling account of response bias and speed-accuracy tradeoffs in a conflict detection task.

Expert decision making often seems impressive, even miraculous. People with genuine expertise in a particular domain can perform quickly and accurately, and with little information. In the series of experiments presented here, we manipulate the amount of “information” available to a group of experts whose job it is to identify the source of crime scene fingerprints. In Experiment 1, we reduced the amount of information available to experts by inverting fingerprint pairs and adding visual noise. There was no evidence for an inversion effect—experts were just as accurate for inverted prints as they were for upright prints—but expert performance with artificially noisy prints was impressive. In Experiment 2, we separated matching and nonmatching print pairs in time. Experts were conservative, but they were still able to discriminate pairs of fingerprints that were separated by five-seconds, even though the task was quite different from their everyday experience. In Experiment 3, we separated the print pairs further in time to test the long-term memory of experts compared to novices. Long-term recognition memory for experts and novices was the same, with both performing around chance. In Experiment 4, we presented pairs of fingerprints quickly to experts and novices in a matching task. Experts were more accurate than novices, particularly for similar nonmatching pairs, and experts were generally more accurate when they had more time. It is clear that experts can match prints accurately when there is reduced visual information, reduced opportunity for direct comparison, and reduced time to engage in deliberate reasoning. These findings suggest that non-analytic processing accounts for a substantial portion of the variance in expert fingerprint matching accuracy. Our conclusion is at odds with general wisdom in fingerprint identification practice and formal training, and at odds with the claims and explanations that are offered in court during expert testimony.

When multisensory integration tasks are performed with an HMD and free-field delivery of sound, as may happen in medicine, transportation, or industry, performance may suffer when the relative location of sound changes as the user moves.

Little is known about the nature and development of fingerprint expertise and, therefore, the best way to turn novices into experts. Little is known about the factors that affect matching accuracy and, therefore, what experts can legitimately testify to in court. This thesis explores the factors that affect matching accuracy and the development of expertise in fingerprint identification, in order to inform training, and to provide an empirical basis for expert testimony in the courtroom. The investigation is grounded in exemplar, signal detection, and dual-process theories, and draws from literature on expertise and skill acquisition, and familiar and unfamiliar face recognition.The thesis comprises four parts. In Part 1-Establishing Expertise-I attempt to find evidence for expert-novice differences in fingerprint matching, and explore where performance differences might lie. In Part 2-Depicting Expertise-I explore alternate methods for presenting signal detection results by depicting the data in a contingency space. In Part 3-Nature of Expertise-I explore the cognitive processes that might account for the superior performance of expert fingerprint examiners, and I explore the limits of rapid expert decision making. In Part 4-Expression of Expertise-I propose a framework for the expression of expert opinion in the courtroom, in order to integrate extra-legal recommendations and emerging research.Taken together, I find that qualified, court-practicing fingerprint examiners are more accurate and more conservative than novices, and that errors are more likely to occur on prints from large databases, which are highly similar but nonmatching. I find that performance, both in terms of accuracy and response bias, changes as people move from novice, to trainee, to expert. I find that experts can discriminate matching and nonmatching prints that are iii artificially noisy, spaced by a short time, briefly flashed on screen, and even when presented in the blink of an eye. These findings indicate that experts make use of non-analytic processing when identifying prints, and they perform accurately when information is sparse-experts can do a lot with a little. Further programs of research, like this one, on the factors that affect fingerprint matching accuracy and performance, will create a foundation for evidence-based training, and serve to increase confidence in the legitimacy of claims made by expert witnesses in the courtroom.iv