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Jason Tangen

The University of Queensland, Australia, School of Psychology, Faculty Member

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I’m a Professor of Cognitive Science in the School of Psychology at The University of Queensland.

I spend most of my time investigating the cognitive processes involved in learning new skills. For example, we’ve been working closely with policing and security agencies to help experts interpret evidence more effectively and reduce the amount of time that it takes to train examiners. I take great pleasure in working across multiple domains from basic visual processes to high level decision making, misinformation, and insight moments.

I received a BASc in Philosophy and Psychology from The University of Lethbridge, in Alberta, Canada where I grew up, and a PhD in Psychology from McMaster University in Hamilton, Ontario, before moving to Sydney in 2004 for a postdoctoral fellowship at UNSW, and joined The University of Queensland in 2006.

I work with some outstanding collaborators, and I have been fortunate to have many wonderful honours and PhD students in my lab.

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Papers by Jason Tangen

Enhancing performance in human decision making: The role of similarity in forensic identification

Proceedings of the 54th Annual Meeting of the Human Factors and Ergonomics Society, 2010

It appears that novice psychology undergraduates can reliably match casework latent crime-scene p... more It appears that novice psychology undergraduates can reliably match casework latent crime-scene prints significantly better than chance (albeit producing a very large number of errors). Their performance is especially impressive when the distractor is a random non-match. Surprisingly, psychology undergraduates can also discriminate matches from highly-similar NAFIS non-matches.
Such demonstrations can establish the benefit of expertise by comparing the performance of forensic examiners with several years of experience to the performance of novices on exactly the same measures.

Accuracy and expertise in human fingerprint identification

Australian Psychology Conferences, 2011

Fingerprint identification has been used in criminal courts for over 100 years but, until now, th... more Fingerprint identification has been used in criminal courts for over 100 years but, until now, there have been no properly controlled experiments on the identification accuracy of human fingerprint examiners. Examiners have even claimed to be infallible, but the US National Academy of Sciences has condemned these claims as scientifically implausible. Here we show that qualified courtpracticing fingerprint experts— from five major state and federal police agencies—are exceedingly accurate compared to novices, but are not infallible. Experts did tend to err on the side of caution, however, by making errors that would free the guilty rather than convict the innocent. Even so, they did make the kind of errors that may lead to false convictions. Interestingly, they were much faster to make a decision when they were right than when they were wrong. Implications for expert testimony are explored as well as the support for nonanalytic processing of fingerprints.

How to cross-examine forensic scientists: A guide for lawyers

Australian Bar Review, 2014

This article is a resource for lawyers approaching the cross-examination of forensic scientists (... more This article is a resource for lawyers approaching the cross-examination of forensic scientists (and other expert witnesses). Through a series of examples, it provides information that will assist lawyers to explore the probative value of forensic science evidence, in particular forensic comparison evidence, on the voir dire and at trial. Questions covering a broad range of potential topics and issues, including relevance, the expression of results, codes of conduct, limitations and errors, are supplemented with detailed commentary and references to authoritative reports and research on the validity and reliability of forensic science techniques.

Nonanalytic cognition: Generalizing without thinking

Experimental Psychology Conference, 2011

Humans are constantly extracting and storing information for future use. How do we process and us... more Humans are constantly extracting and storing information for future use. How do we process and use information in selecting a wine, making a medical diagnosis, or appreciating art? In distinguishing Picasso’s from Monet’s painting style, it seems obvious that we would consciously consider the requisite features that describe each artist’s work. To test our thinking in this context, we stripped the nameable features, such as mandolins and waterlilies, from their paintings and showed that enough information remained to distinguish them. However, participants were only able to perform this task if their analysis was diverted away from the ways that the paintings differed. We then showed that those who learned the reduced images could transfer this learning to new instances of full paintings and vice versa, even though this transfer cannot be attributed to nameable features. Our conclusion is that people routinely rely on presymbolic information in episodic memory and other higher cognitive tasks, even when dealing with materials that are rich in specific meaning and nameable features.

Expertise, memory, and nonanalytic cognition in fingerprint matching: Experts can discriminate prints in noise, spaced in time, and in the blink of an eye

Proceedings of the 40th Australasian Experimental Psychology Conference, 2013

When a fingerprint is found at a crime scene it is a human expert, not a machine, who is faced wi... more When a fingerprint is found at a crime scene it is a human expert, not a machine, who is faced with the task of identifying the person who left it. We know from similar domains of expertise, such as medical diagnosis, that experts are accurate even with very little information and that much of expert decision making is based on rapid and unconscious recognition of previously encountered instances-nonanalytic cognition. Here I will present evidence for nonanalytic cognition in fingerprint matching, such that experts can discriminate fingerprints in noise, spaced in time, and in two seconds. Unexpectedly, however, fingerprint experts did not show the classic inversion effect seen in face recognition.

Evidence for expertise in fingerprint identification and the ramifications for the future study of forensic expertise

American Academy of Forensic Science Annual Meeting, 2012

Attendees will receive an overview of recent criticisms of forensic identification; be updated on... more Attendees will receive an overview of recent criticisms of forensic identification; be updated on the findings of and rationale behind recent studies of expertise in fingerprint identification; and understand the implications of these experiments for expert testimony and public policy. Impact Statement: This presentation will provide a rationale for the design of recent experiments on forensic expertise and put the experimental results in context for the benefit of forensic researchers, examiners, managers, and policy makers. Abstract: Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. In 2009, the National Academy of Sciences (NAS) delivered a landmark report highlighting the absence of solid scientific methods and practices in the forensic science domain.1 Harry T. Edwards (a senior US judge and co-chair of the NAS Committee) noted that forensic science disciplines, including fingerprints, are typically not grounded in scientific methodology, and forensic experts are not bound by solid practices that ensure that the forensic evidence that is offered in court is valid and reliable.2 The NAS recommended that the US Congress fund basic research to help the forensic community strengthen their field, develop valid and reliable measures of performance, and establish evidence-based standards for analyzing and reporting testimony. Recently, researchers have investigated the effect of contextual bias on fingerprint examiners; some of the special abilities and vulnerabilities of fingerprint examiners; the effect of technology; statistical models of fingerprint identification; and the accuracy of fingerprint examiners’ decisions. Despite this contribution, there are still few peer-reviewed studies directly examining the extent to which experts can correctly match fingerprints to one another, how competent and proficient fingerprint experts are, how and on what basis examiners make their decisions, and what factors affect matching accuracy. The “Identifying Fingerprint Expertise? experiment was designed to find out whether fingerprint experts were any more accurate at matching prints than the average person, and to get an idea of how often they make errors of the sort that could lead to a failure to identify a criminal compared to how often they make errors of the sort that could lead to inaccurate evidence being presented in court.3 Results show that qualified, court-practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. In this presentation, a rationale for the design of the experiment will be provided, as well as context for interpreting the results for the benefit of researchers, forensic examiners, forensic managers, lawyers, and judges. It will be argued that fidelity, generalizability and control must be balanced in order to answer important research questions; that the proficiency and competence of fingerprint examiners is best determined when experiments include highly similar print pairs, in a signal detection paradigm, where the ground truth is known; that determining error rates with system-wide black box studies may be inefficient at best and unnecessary at worst; and that inferring from this experiment the statement “The error rate of fingerprint identification is 0.68%" would be disingenuous.4 In closing, the ramifications of these findings for the future study of forensic expertise, and the implications for expert testimony and public policy will be presented.

Humans matching fingerprints: Sequence and Size

Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 2010

Television shows like ‘CSI’ can give the impression that matching crime-scene fingerprints is ful... more Television shows like ‘CSI’ can give the impression that matching crime-scene fingerprints is fully automated. But it is actually humans (fingerprint experts) who ultimately decide whether a crime-scene print belongs to a suspect or not. Despite this fact, there have been no published, peer-reviewed studies directly examining the extent to which experts can correctly match fingerprints to one another. In two experiments presented here we aim to determine the factors affecting accuracy using non-expert participants and test (1) whether the advantage found for the sequential presentation of faces applies to prints and (2) whether the amount of information in a print matters.

The importance of ground truth: An open-source biometric repository

Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 2010

Advances in forensic technologies and procedures seek to produce better and more efficient polici... more Advances in forensic technologies and procedures seek to produce better and more efficient policing for safer societies. Little is understood, however, about how effectively the human forensic professional employs such technologies, or the cognitive and perceptual processes of judgment and decision making the forensic professional engages in during the course of evidence evaluation. For this, experimenters need materials that approximate the realism of crime scene evidence, while ensuring the ground truth about the source of this information. These two goals are often incompatible. We discuss the development of an open-source biometric repository to address the issue of ground truth. This repository contains a range of crime related materials such as fingerprints and palm-prints, shoe-prints, faces, handwriting, voices, and irises. Our goal is to provide a large, open-source repository of forensic information, where certainty of the source in built into the system, to help advance research on identification by humans and technology.

Temporal contiguity and contingency judgments: A Pavlovian analogue

Integrative Physiological And Behavioral Science, 2003

The two experiments reported examine the role of temporal contiguity on judgments of contingency ... more The two experiments reported examine the role of temporal contiguity on judgments of contingency in a human analogue of the Pavlovian task. The data show that the effect of the actual delay on contingency judgment depends on the observer's expectation regarding the delay. For a fixed contingency between the cue and the outcome, ratings of the contingency are higher when the actual delay is congruent with the observer's expectation than when it is incongruent. We argue that our data can be understood within the context of the temporal coding hypothesis.

On visual kin recognition and family resemblance in chimpanzees

Journal of Comparative Psychology, 2004

The results of Parr and de Waal (1999) on male-offspring biased visual kin recognition in chimpan... more The results of Parr and de Waal (1999) on male-offspring biased visual kin recognition in chimpanzees was replicated using both human judgements, and a principal components analysis (PCA) applied to pixel-maps. With the same matching to sample paradigm and stimulus sets as used by Parr and de Waal (1999), both humans and the PCA produced the same sex-biased kin recognition as that found with the chimpanzees. The PCA suggested that the basis of the sex-based bias in kin recognition could be a function of the similarity in the "framing" of the photographs of mothers and their sons, but not daughters. Eliminating the potential framing bias, either by cropping the photos (Experiment 2) or rebalancing the recognition foils (Experiment 3), also eliminated the sex bias, but not the recognition of chimpanzee kin with human participants. whose earlier work with autoassociative neural network models of face perception served as a model for the current research. Finally, the first author would like to thank Martin Daly, who first introduced him to the psychological issues underlying the problem of kin recognition.

Cue interaction and judgments of causality: Contributions of causal and associative processes

Memory & Cognition, 2004

In four experiments, the predictions made by causal model theory and the Rescorla-Wagner model we... more In four experiments, the predictions made by causal model theory and the Rescorla-Wagner model were tested by using a cue interaction paradigm that measures the relative response to a given event based on the influence or salience of an alternative event. Experiments 1 and 2 uncorrelated two variables that have typically been confounded in the literature (causal order and the number of cues and outcomes) and demonstrated that overall contingency judgments are influenced by the causal structure of the events. Experiment 3 showed that trial-by-trial prediction responses, a second measure of causal assessment, were not influenced by the causal structure of the described events. Experiment 4 revealed that participants became less sensitive to the influence of the causal structure in both their ratings and their predictions as trials progressed. Thus, two experiments provided evidence for highlevel (causal reasoning) processes, and two experiments provided evidence for low-level (associative) processes. We argue that both factors influence causal assessment, depending on what is being asked about the events and participants’ experience with those events.

A signal detection analysis of contingency data

Learning & Behaviour, 2005

There are many psychological tasks that involve the pairing of binary variables. The various task... more There are many psychological tasks that involve the pairing of binary variables. The various tasks used often address different questions and are motivated by different theoretical issues and traditions. Upon closer examination, however, the tasks are remarkably similar in structure. In the present paper, we examine two such tasks, the contingency judgment task and the signal detection task, and we apply a signal detection analysis to contingency judgment data. We suggest that the signal detection analysis provides a novel interpretation of a well-established but poorly understood phenomenon of contingency judgments-the outcome-density effect.

Judging relationships between events: How do we do it

Canadian Journal of Experimental Psychology, 2005

A decade ago, Allan (1993) concluded that associative models provided the best account of data ge... more A decade ago, Allan (1993) concluded that associative models provided the best account of data generated in tasks that require human observers to judge the relationship between binary events. In the intervening years, new data have been reported that provide evidence for higher-order processes. Some have argued that these new data pose a serious threat to the viability of the associative account. The purpose of the present paper is to review this evidence and to assess the severity of this threat.

Unintended effects of memory on decision making: A breakdown in access control

Journal of Memory and Language, 2010

A hybrid evaluative-conditioning/source-monitoring paradigm is put forward as an alternative to t... more A hybrid evaluative-conditioning/source-monitoring paradigm is put forward as an alternative to the standard evaluative-conditioning paradigm. The first experiment paired brand names with a small number of attractive or unattractive female faces and used a likeability rating task as well as a source monitoring task. The second experiment paired words which differed along a masculine-feminine dimension with male and female faces, and used a speeded judgment about whether words were stereotypically masculine or feminine. The third experiment paired words that differed along an active-inactive dimension with male and female faces and used a variation of the Implicit Association Test where judgments about whether words were active or inactive were mixed with judgments about whether faces were male or female. In all three experiments, we observed transfer between the recently acquired information and the judgment task. In addition, the three experiments progressively reduce the probability of demand characteristics. We explain the results in this paradigm, and in many other paradigms, as a breakdown in access control. We also point to several similarities between existing theories of evaluative conditioning and memory phenomena/theories that have gone unnoticed in the evaluative conditioning literature.

Flashed face distortion effect: Grotesque faces from relative spaces

Perception, 2011

We discovered an interesting face distortion effect while preparing a set of face images for an i... more We discovered an interesting face distortion effect while preparing a set of face images for an identification experiment. We obtained a set of faces from a Slovakian database (SmartNet IBC, no date) and eye-aligned them using PsychoMorph (Tiddeman et al 2001). To check the consistency of the eye alignment, we started skimming through the images on the computer at a fast pace. After a while, we made a few remarks to one another about the`aesthetically challenged' faces in the set. They began to appear highly deformed and grotesque. But after inspecting the especially ugly faces individually, each of them appeared normal or even attractive. It seemed that, after continuously flipping through the eye-aligned faces at a steady rate, each one began to appear as a caricature of itself. If a person had a large jaw, it looked particularly large, almost ogre-like. If a person had a slender nose, then it looked remarkably thin. Many of the distortions, however, were quite difficult to articulate. If we stopped the sequence and returned to these particular faces, however, they quickly returned to normal. We entertained the idea that Slavic faces were inherently bizarre, but we replicated the effect with faces from several other databases. We standardised the presentation rate and found that roughly 4^5 faces per second was ideal (see Movie 1 in the Supplementary Online Material at http://dx.doi.org/10.1068/ p6968). After gazing at a continuous sequence for a minute or so, many of the faces will appear highly distorted, even monstrous. The degree of distortion is greatest for faces that deviate from the others in the set on a particular dimension. If one face has an especially large or pronounced forehead compared to the others in the set, for example, then it appears particularly bulbous. Relative encoding seems to drive the effect. That is, forcing the observer to encode each face in light of the others. By eye-aligning the faces, it becomes much easier to compare their shape and the relative location of their features, so the differences between them become more evident. The fast, steady presentation rate may also encourage this relative encoding. If the faces are not eye-aligned or if they are presented too slowly or quickly, then the effect lessens. Or, if we insert a brief gap in the sequence, the effect almost completely disappears (see Movie 2). This effect is most certainly related to work on adaptation, and the`face distortion after effect' specifically (Webster and MacLin 1999). In the basic paradigm, participants study a single artificially distorted face for a few seconds to several minutes followed SHORT AND SWEET Flashed face distortion effect: Grotesque faces from relative spaces Perception, 2011, volume 40, pages 628^630 Abstract. We describe a novel face distortion effect resulting from the fast-paced presentation of eye-aligned faces. When cycling through the faces on a computer screen, each face seems to become a caricature of itself and some faces appear highly deformed, even grotesque. The degree of distortion is greatest for faces that deviate from the others in the set on a particular dimension (eg if a person has a large forehead, it looks particularly large). This new method of image presentation, based on alignment and speed, could provide a useful tool for investigating contrastive distortion effects and face adaptation.

Expertise in fingerprint identification

Journal of Forensic Sciences, 2013

Although fingerprint experts have presented evidence in criminal courts for more than a century, ... more Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. A recent latent print matching experiment shows that qualified, court-practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. Here, a rationale for the design of this experiment is provided. We argue that fidelity, generalizability, and control must be balanced to answer important research questions; that the proficiency and competence of fingerprint examiners are best determined when experiments include highly similar print pairs, in a signal detection paradigm, where the ground truth is known; and that inferring from this experiment the statement "The error rate of fingerprint identification is 0.68%" would be unjustified. In closing, the ramifications of these findings for the future psychological study of forensic expertise and the implications for expert testimony and public policy are considered.

Identification personified

Australian Journal of Forensic Sciences, 2013

Forensic practitioners are beginning to acknowledge that there is more to identifying trace evide... more Forensic practitioners are beginning to acknowledge that there is more to identifying trace evidence than the methodology on which they rely. Instead, identification is based on human decision making, which is prone to error. The problem is that we know very little about how these decisions are made, how often errors arise, what to do about them if they occur, and how to acknowledge the risk of error in courts. Dealing with errors in forensic science is not simply a matter of ‘getting rid of the bad apples’. Instead, we must develop resilient systems that identify and enhance the positive capacities of people and organisations that allow them to adapt effectively under pressure. The recognition of error in forensic practice is an excellent first step in strengthening the field, but ‘more and better research’ still needs to be conducted to understand better the nature of expertise in identification to improve training and the value of expert testimony.

Understanding expertise and non-analytic cognition in fingerprint discriminations made by humans

Frontiers in Psychology, 2014

Human matching performance of genuine crime scene latent fingerprints

Law and Human Behavior, 2014

There has been very little research into the nature and development of fingerprint matching exper... more There has been very little research into the nature and development of fingerprint matching expertise. Here we present the results of an experiment testing the claimed matching expertise of fingerprint examiners. Expert (n = 37), intermediate trainee (n = 8), new trainee (n = 9), and novice (n = 37) participants performed a fingerprint discrimination task involving genuine crime scene latent fingerprints, their matches, and highly similar distractors, in a signal detection paradigm. Results show that qualified, court-practicing fingerprint experts were exceedingly accurate compared with novices. Experts showed a conservative response bias, tending to err on the side of caution by making more errors of the sort that could allow a guilty person to escape detection than errors of the sort that could falsely incriminate an innocent person. The superior performance of experts was not simply a function of their ability to match prints, per se, but a result of their ability to identify the highly similar, but nonmatching fingerprints as such. Comparing these results with previous experiments, experts were even more conservative in their decision making when dealing with these genuine crime scene prints than when dealing with simulated crime scene prints, and this conservatism made them relatively less accurate overall. Intermediate trainees-despite their lack of qualification and average 3.5 years experience-performed about as accurately as qualified experts who had an average 17.5 years experience. New trainees-despite their 5-week, full-time training course or their 6 months experience-were not any better than novices at discriminating matching and similar nonmatching prints, they were just more conservative. Further research is required to determine the precise nature of fingerprint matching expertise and the factors that influence performance. The findings of this representative, lab-based experiment may have implications for the way fingerprint examiners testify in court, but what the findings mean for reasoning about expert performance in the wild is an open, empirical, and epistemological question.

Generalization in fingerprint matching experiments

Science & Justice, 2014

Enhancing performance in human decision making: The role of similarity in forensic identification

Proceedings of the 54th Annual Meeting of the Human Factors and Ergonomics Society, 2010

It appears that novice psychology undergraduates can reliably match casework latent crime-scene p... more It appears that novice psychology undergraduates can reliably match casework latent crime-scene prints significantly better than chance (albeit producing a very large number of errors). Their performance is especially impressive when the distractor is a random non-match. Surprisingly, psychology undergraduates can also discriminate matches from highly-similar NAFIS non-matches.
Such demonstrations can establish the benefit of expertise by comparing the performance of forensic examiners with several years of experience to the performance of novices on exactly the same measures.

Accuracy and expertise in human fingerprint identification

Australian Psychology Conferences, 2011

Fingerprint identification has been used in criminal courts for over 100 years but, until now, th... more Fingerprint identification has been used in criminal courts for over 100 years but, until now, there have been no properly controlled experiments on the identification accuracy of human fingerprint examiners. Examiners have even claimed to be infallible, but the US National Academy of Sciences has condemned these claims as scientifically implausible. Here we show that qualified courtpracticing fingerprint experts— from five major state and federal police agencies—are exceedingly accurate compared to novices, but are not infallible. Experts did tend to err on the side of caution, however, by making errors that would free the guilty rather than convict the innocent. Even so, they did make the kind of errors that may lead to false convictions. Interestingly, they were much faster to make a decision when they were right than when they were wrong. Implications for expert testimony are explored as well as the support for nonanalytic processing of fingerprints.

How to cross-examine forensic scientists: A guide for lawyers

Australian Bar Review, 2014

This article is a resource for lawyers approaching the cross-examination of forensic scientists (... more This article is a resource for lawyers approaching the cross-examination of forensic scientists (and other expert witnesses). Through a series of examples, it provides information that will assist lawyers to explore the probative value of forensic science evidence, in particular forensic comparison evidence, on the voir dire and at trial. Questions covering a broad range of potential topics and issues, including relevance, the expression of results, codes of conduct, limitations and errors, are supplemented with detailed commentary and references to authoritative reports and research on the validity and reliability of forensic science techniques.

Nonanalytic cognition: Generalizing without thinking

Experimental Psychology Conference, 2011

Humans are constantly extracting and storing information for future use. How do we process and us... more Humans are constantly extracting and storing information for future use. How do we process and use information in selecting a wine, making a medical diagnosis, or appreciating art? In distinguishing Picasso’s from Monet’s painting style, it seems obvious that we would consciously consider the requisite features that describe each artist’s work. To test our thinking in this context, we stripped the nameable features, such as mandolins and waterlilies, from their paintings and showed that enough information remained to distinguish them. However, participants were only able to perform this task if their analysis was diverted away from the ways that the paintings differed. We then showed that those who learned the reduced images could transfer this learning to new instances of full paintings and vice versa, even though this transfer cannot be attributed to nameable features. Our conclusion is that people routinely rely on presymbolic information in episodic memory and other higher cognitive tasks, even when dealing with materials that are rich in specific meaning and nameable features.

Expertise, memory, and nonanalytic cognition in fingerprint matching: Experts can discriminate prints in noise, spaced in time, and in the blink of an eye

Proceedings of the 40th Australasian Experimental Psychology Conference, 2013

When a fingerprint is found at a crime scene it is a human expert, not a machine, who is faced wi... more When a fingerprint is found at a crime scene it is a human expert, not a machine, who is faced with the task of identifying the person who left it. We know from similar domains of expertise, such as medical diagnosis, that experts are accurate even with very little information and that much of expert decision making is based on rapid and unconscious recognition of previously encountered instances-nonanalytic cognition. Here I will present evidence for nonanalytic cognition in fingerprint matching, such that experts can discriminate fingerprints in noise, spaced in time, and in two seconds. Unexpectedly, however, fingerprint experts did not show the classic inversion effect seen in face recognition.

Evidence for expertise in fingerprint identification and the ramifications for the future study of forensic expertise

American Academy of Forensic Science Annual Meeting, 2012

Attendees will receive an overview of recent criticisms of forensic identification; be updated on... more Attendees will receive an overview of recent criticisms of forensic identification; be updated on the findings of and rationale behind recent studies of expertise in fingerprint identification; and understand the implications of these experiments for expert testimony and public policy. Impact Statement: This presentation will provide a rationale for the design of recent experiments on forensic expertise and put the experimental results in context for the benefit of forensic researchers, examiners, managers, and policy makers. Abstract: Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. In 2009, the National Academy of Sciences (NAS) delivered a landmark report highlighting the absence of solid scientific methods and practices in the forensic science domain.1 Harry T. Edwards (a senior US judge and co-chair of the NAS Committee) noted that forensic science disciplines, including fingerprints, are typically not grounded in scientific methodology, and forensic experts are not bound by solid practices that ensure that the forensic evidence that is offered in court is valid and reliable.2 The NAS recommended that the US Congress fund basic research to help the forensic community strengthen their field, develop valid and reliable measures of performance, and establish evidence-based standards for analyzing and reporting testimony. Recently, researchers have investigated the effect of contextual bias on fingerprint examiners; some of the special abilities and vulnerabilities of fingerprint examiners; the effect of technology; statistical models of fingerprint identification; and the accuracy of fingerprint examiners’ decisions. Despite this contribution, there are still few peer-reviewed studies directly examining the extent to which experts can correctly match fingerprints to one another, how competent and proficient fingerprint experts are, how and on what basis examiners make their decisions, and what factors affect matching accuracy. The “Identifying Fingerprint Expertise? experiment was designed to find out whether fingerprint experts were any more accurate at matching prints than the average person, and to get an idea of how often they make errors of the sort that could lead to a failure to identify a criminal compared to how often they make errors of the sort that could lead to inaccurate evidence being presented in court.3 Results show that qualified, court-practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. In this presentation, a rationale for the design of the experiment will be provided, as well as context for interpreting the results for the benefit of researchers, forensic examiners, forensic managers, lawyers, and judges. It will be argued that fidelity, generalizability and control must be balanced in order to answer important research questions; that the proficiency and competence of fingerprint examiners is best determined when experiments include highly similar print pairs, in a signal detection paradigm, where the ground truth is known; that determining error rates with system-wide black box studies may be inefficient at best and unnecessary at worst; and that inferring from this experiment the statement “The error rate of fingerprint identification is 0.68%" would be disingenuous.4 In closing, the ramifications of these findings for the future study of forensic expertise, and the implications for expert testimony and public policy will be presented.

Humans matching fingerprints: Sequence and Size

Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 2010

Television shows like ‘CSI’ can give the impression that matching crime-scene fingerprints is ful... more Television shows like ‘CSI’ can give the impression that matching crime-scene fingerprints is fully automated. But it is actually humans (fingerprint experts) who ultimately decide whether a crime-scene print belongs to a suspect or not. Despite this fact, there have been no published, peer-reviewed studies directly examining the extent to which experts can correctly match fingerprints to one another. In two experiments presented here we aim to determine the factors affecting accuracy using non-expert participants and test (1) whether the advantage found for the sequential presentation of faces applies to prints and (2) whether the amount of information in a print matters.

The importance of ground truth: An open-source biometric repository

Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 2010

Advances in forensic technologies and procedures seek to produce better and more efficient polici... more Advances in forensic technologies and procedures seek to produce better and more efficient policing for safer societies. Little is understood, however, about how effectively the human forensic professional employs such technologies, or the cognitive and perceptual processes of judgment and decision making the forensic professional engages in during the course of evidence evaluation. For this, experimenters need materials that approximate the realism of crime scene evidence, while ensuring the ground truth about the source of this information. These two goals are often incompatible. We discuss the development of an open-source biometric repository to address the issue of ground truth. This repository contains a range of crime related materials such as fingerprints and palm-prints, shoe-prints, faces, handwriting, voices, and irises. Our goal is to provide a large, open-source repository of forensic information, where certainty of the source in built into the system, to help advance research on identification by humans and technology.

Temporal contiguity and contingency judgments: A Pavlovian analogue

Integrative Physiological And Behavioral Science, 2003

The two experiments reported examine the role of temporal contiguity on judgments of contingency ... more The two experiments reported examine the role of temporal contiguity on judgments of contingency in a human analogue of the Pavlovian task. The data show that the effect of the actual delay on contingency judgment depends on the observer's expectation regarding the delay. For a fixed contingency between the cue and the outcome, ratings of the contingency are higher when the actual delay is congruent with the observer's expectation than when it is incongruent. We argue that our data can be understood within the context of the temporal coding hypothesis.

On visual kin recognition and family resemblance in chimpanzees

Journal of Comparative Psychology, 2004

The results of Parr and de Waal (1999) on male-offspring biased visual kin recognition in chimpan... more The results of Parr and de Waal (1999) on male-offspring biased visual kin recognition in chimpanzees was replicated using both human judgements, and a principal components analysis (PCA) applied to pixel-maps. With the same matching to sample paradigm and stimulus sets as used by Parr and de Waal (1999), both humans and the PCA produced the same sex-biased kin recognition as that found with the chimpanzees. The PCA suggested that the basis of the sex-based bias in kin recognition could be a function of the similarity in the "framing" of the photographs of mothers and their sons, but not daughters. Eliminating the potential framing bias, either by cropping the photos (Experiment 2) or rebalancing the recognition foils (Experiment 3), also eliminated the sex bias, but not the recognition of chimpanzee kin with human participants. whose earlier work with autoassociative neural network models of face perception served as a model for the current research. Finally, the first author would like to thank Martin Daly, who first introduced him to the psychological issues underlying the problem of kin recognition.

Cue interaction and judgments of causality: Contributions of causal and associative processes

Memory & Cognition, 2004

In four experiments, the predictions made by causal model theory and the Rescorla-Wagner model we... more In four experiments, the predictions made by causal model theory and the Rescorla-Wagner model were tested by using a cue interaction paradigm that measures the relative response to a given event based on the influence or salience of an alternative event. Experiments 1 and 2 uncorrelated two variables that have typically been confounded in the literature (causal order and the number of cues and outcomes) and demonstrated that overall contingency judgments are influenced by the causal structure of the events. Experiment 3 showed that trial-by-trial prediction responses, a second measure of causal assessment, were not influenced by the causal structure of the described events. Experiment 4 revealed that participants became less sensitive to the influence of the causal structure in both their ratings and their predictions as trials progressed. Thus, two experiments provided evidence for highlevel (causal reasoning) processes, and two experiments provided evidence for low-level (associative) processes. We argue that both factors influence causal assessment, depending on what is being asked about the events and participants’ experience with those events.

A signal detection analysis of contingency data

Learning & Behaviour, 2005

There are many psychological tasks that involve the pairing of binary variables. The various task... more There are many psychological tasks that involve the pairing of binary variables. The various tasks used often address different questions and are motivated by different theoretical issues and traditions. Upon closer examination, however, the tasks are remarkably similar in structure. In the present paper, we examine two such tasks, the contingency judgment task and the signal detection task, and we apply a signal detection analysis to contingency judgment data. We suggest that the signal detection analysis provides a novel interpretation of a well-established but poorly understood phenomenon of contingency judgments-the outcome-density effect.

Judging relationships between events: How do we do it

Canadian Journal of Experimental Psychology, 2005

A decade ago, Allan (1993) concluded that associative models provided the best account of data ge... more A decade ago, Allan (1993) concluded that associative models provided the best account of data generated in tasks that require human observers to judge the relationship between binary events. In the intervening years, new data have been reported that provide evidence for higher-order processes. Some have argued that these new data pose a serious threat to the viability of the associative account. The purpose of the present paper is to review this evidence and to assess the severity of this threat.

Unintended effects of memory on decision making: A breakdown in access control

Journal of Memory and Language, 2010

A hybrid evaluative-conditioning/source-monitoring paradigm is put forward as an alternative to t... more A hybrid evaluative-conditioning/source-monitoring paradigm is put forward as an alternative to the standard evaluative-conditioning paradigm. The first experiment paired brand names with a small number of attractive or unattractive female faces and used a likeability rating task as well as a source monitoring task. The second experiment paired words which differed along a masculine-feminine dimension with male and female faces, and used a speeded judgment about whether words were stereotypically masculine or feminine. The third experiment paired words that differed along an active-inactive dimension with male and female faces and used a variation of the Implicit Association Test where judgments about whether words were active or inactive were mixed with judgments about whether faces were male or female. In all three experiments, we observed transfer between the recently acquired information and the judgment task. In addition, the three experiments progressively reduce the probability of demand characteristics. We explain the results in this paradigm, and in many other paradigms, as a breakdown in access control. We also point to several similarities between existing theories of evaluative conditioning and memory phenomena/theories that have gone unnoticed in the evaluative conditioning literature.

Flashed face distortion effect: Grotesque faces from relative spaces

Perception, 2011

We discovered an interesting face distortion effect while preparing a set of face images for an i... more We discovered an interesting face distortion effect while preparing a set of face images for an identification experiment. We obtained a set of faces from a Slovakian database (SmartNet IBC, no date) and eye-aligned them using PsychoMorph (Tiddeman et al 2001). To check the consistency of the eye alignment, we started skimming through the images on the computer at a fast pace. After a while, we made a few remarks to one another about the`aesthetically challenged' faces in the set. They began to appear highly deformed and grotesque. But after inspecting the especially ugly faces individually, each of them appeared normal or even attractive. It seemed that, after continuously flipping through the eye-aligned faces at a steady rate, each one began to appear as a caricature of itself. If a person had a large jaw, it looked particularly large, almost ogre-like. If a person had a slender nose, then it looked remarkably thin. Many of the distortions, however, were quite difficult to articulate. If we stopped the sequence and returned to these particular faces, however, they quickly returned to normal. We entertained the idea that Slavic faces were inherently bizarre, but we replicated the effect with faces from several other databases. We standardised the presentation rate and found that roughly 4^5 faces per second was ideal (see Movie 1 in the Supplementary Online Material at http://dx.doi.org/10.1068/ p6968). After gazing at a continuous sequence for a minute or so, many of the faces will appear highly distorted, even monstrous. The degree of distortion is greatest for faces that deviate from the others in the set on a particular dimension. If one face has an especially large or pronounced forehead compared to the others in the set, for example, then it appears particularly bulbous. Relative encoding seems to drive the effect. That is, forcing the observer to encode each face in light of the others. By eye-aligning the faces, it becomes much easier to compare their shape and the relative location of their features, so the differences between them become more evident. The fast, steady presentation rate may also encourage this relative encoding. If the faces are not eye-aligned or if they are presented too slowly or quickly, then the effect lessens. Or, if we insert a brief gap in the sequence, the effect almost completely disappears (see Movie 2). This effect is most certainly related to work on adaptation, and the`face distortion after effect' specifically (Webster and MacLin 1999). In the basic paradigm, participants study a single artificially distorted face for a few seconds to several minutes followed SHORT AND SWEET Flashed face distortion effect: Grotesque faces from relative spaces Perception, 2011, volume 40, pages 628^630 Abstract. We describe a novel face distortion effect resulting from the fast-paced presentation of eye-aligned faces. When cycling through the faces on a computer screen, each face seems to become a caricature of itself and some faces appear highly deformed, even grotesque. The degree of distortion is greatest for faces that deviate from the others in the set on a particular dimension (eg if a person has a large forehead, it looks particularly large). This new method of image presentation, based on alignment and speed, could provide a useful tool for investigating contrastive distortion effects and face adaptation.

Expertise in fingerprint identification

Journal of Forensic Sciences, 2013

Although fingerprint experts have presented evidence in criminal courts for more than a century, ... more Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. A recent latent print matching experiment shows that qualified, court-practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. Here, a rationale for the design of this experiment is provided. We argue that fidelity, generalizability, and control must be balanced to answer important research questions; that the proficiency and competence of fingerprint examiners are best determined when experiments include highly similar print pairs, in a signal detection paradigm, where the ground truth is known; and that inferring from this experiment the statement "The error rate of fingerprint identification is 0.68%" would be unjustified. In closing, the ramifications of these findings for the future psychological study of forensic expertise and the implications for expert testimony and public policy are considered.

Identification personified

Australian Journal of Forensic Sciences, 2013

Forensic practitioners are beginning to acknowledge that there is more to identifying trace evide... more Forensic practitioners are beginning to acknowledge that there is more to identifying trace evidence than the methodology on which they rely. Instead, identification is based on human decision making, which is prone to error. The problem is that we know very little about how these decisions are made, how often errors arise, what to do about them if they occur, and how to acknowledge the risk of error in courts. Dealing with errors in forensic science is not simply a matter of ‘getting rid of the bad apples’. Instead, we must develop resilient systems that identify and enhance the positive capacities of people and organisations that allow them to adapt effectively under pressure. The recognition of error in forensic practice is an excellent first step in strengthening the field, but ‘more and better research’ still needs to be conducted to understand better the nature of expertise in identification to improve training and the value of expert testimony.

Understanding expertise and non-analytic cognition in fingerprint discriminations made by humans

Frontiers in Psychology, 2014

Human matching performance of genuine crime scene latent fingerprints

Law and Human Behavior, 2014

There has been very little research into the nature and development of fingerprint matching exper... more There has been very little research into the nature and development of fingerprint matching expertise. Here we present the results of an experiment testing the claimed matching expertise of fingerprint examiners. Expert (n = 37), intermediate trainee (n = 8), new trainee (n = 9), and novice (n = 37) participants performed a fingerprint discrimination task involving genuine crime scene latent fingerprints, their matches, and highly similar distractors, in a signal detection paradigm. Results show that qualified, court-practicing fingerprint experts were exceedingly accurate compared with novices. Experts showed a conservative response bias, tending to err on the side of caution by making more errors of the sort that could allow a guilty person to escape detection than errors of the sort that could falsely incriminate an innocent person. The superior performance of experts was not simply a function of their ability to match prints, per se, but a result of their ability to identify the highly similar, but nonmatching fingerprints as such. Comparing these results with previous experiments, experts were even more conservative in their decision making when dealing with these genuine crime scene prints than when dealing with simulated crime scene prints, and this conservatism made them relatively less accurate overall. Intermediate trainees-despite their lack of qualification and average 3.5 years experience-performed about as accurately as qualified experts who had an average 17.5 years experience. New trainees-despite their 5-week, full-time training course or their 6 months experience-were not any better than novices at discriminating matching and similar nonmatching prints, they were just more conservative. Further research is required to determine the precise nature of fingerprint matching expertise and the factors that influence performance. The findings of this representative, lab-based experiment may have implications for the way fingerprint examiners testify in court, but what the findings mean for reasoning about expert performance in the wild is an open, empirical, and epistemological question.

Generalization in fingerprint matching experiments

Science & Justice, 2014