PhD Research
Perceptual Expertise in High-Stakes Decisions
What separates those who reach exceptional performance from those who do not?
The Stakes
Fingerprint examination plays a critical role in forensic identification, yet relies heavily on subjective comparisons by expert examiners. Mistakes can have severe consequences—wrongful convictions or guilty parties going free.
Despite fingerprints serving as identification evidence for over a century, scientific bodies have called for more research on the validity and reliability of fingerprint analysis. Understanding the psychological mechanisms underlying expertise is essential for ensuring accuracy in this high-stakes domain.
Why This Matters
Examiners spend hours comparing prints from crime scenes to potential matches. Their judgments directly impact justice outcomes. Yet the cognitive processes underlying their expertise have remained largely unexamined.
The Research Program
This PhD research used fingerprint identification as an ecological testbed to explore the complex knowledge structures, cognitive processes, and personal faculties that lead to exceptional performance. Across three studies, I employed a mixed-methods approach to reverse engineer expertise.
Three Complementary Investigations
How Experts Think
Think-aloud protocols capturing cognitive processes during fingerprint analysis
Protocol AnalysisHow Experts Remember
Visual short-term memory for domain-specific stimuli and print distinctiveness
Memory ExperimentsWhat Predicts Expertise
Cognitive abilities and personality traits that distinguish experts from novices
Individual DifferencesHow Experts Think
Using think-aloud protocols with 44 fingerprint examiners and 44 novices, we discovered that expertise is not just about knowing more—it's about thinking differently.
Attentional Focus
Experts focused on local ridge characteristics and minute details, while novices concentrated on global features.
Adaptive Strategy
Experts demonstrated adaptability in dynamically planning their systematic approach to each unique print.
Domain Knowledge
Experts integrated specialised knowledge of causal biological and mechanical factors affecting prints.
Critical Evaluation
Experts displayed metacognition, carefully weighing the reliability of each identifying feature before concluding.
"Becoming an expert is not just about knowing more; it is about thinking differently. This qualitative shift in cognition redefines the way experts engage with their domain."
How Experts Remember
Superior memory may be integral to attaining and maintaining proficiency in fingerprint examination. Across two experiments, we tested whether expertise enhances visual short-term memory for domain-specific stimuli.
Experiment 1
Experts showed substantially higher memory performance compared to novices for fingerprints from their domain of expertise.
44 experts vs 44 novicesExperiment 2
While both groups benefited from distinctive prints, experts still outperformed novices especially for nondistinctive prints—the harder cases.
Distinctiveness manipulationWhat This Means
Beyond stimulus qualities, expertise itself enhances short-term memory, likely through more effective organisational processing and sensitivity to meaningful patterns. This suggests training to improve memory for diverse fingerprints could practically boost examiner performance.
What Predicts Expertise
If certain inherent traits predict expertise, screening based on these factors may help identify candidates most likely to excel. We compared 42 fingerprint experts with 42 novices across cognitive tasks and personality measures.
Cognitive Tasks
- Visual search
- Mental rotation
- Inhibition
- Intelligence measures
Personality Measures
- Big Five traits
- Risk propensity
- Intolerance of uncertainty
- Resilience
However, the predictive power of these traits was subtle and was overshadowed by domain-specific perceptual skills (measured by the Fingerprint Expertise Quotient). Extensive experience in the field emerged as the dominant force.
The Takeaway
Expertise in fingerprint identification demands a blend of specialised experience and effective training, while also benefiting from certain innate abilities and traits.
Given the gravity of fingerprint analysis for security, justice, and liberty, applying these insights to strengthen training and practice is an ethical imperative. By refining selection and instruction grounded in science, we can nurture and empower experts to reach their full potential.
Implications
Training Design
Balance intuitive pattern recognition with analytical reasoning. Emphasise diverse exposure to varied exemplars.
Memory Enhancement
Training programs could focus on improving memory for diverse fingerprints to boost practical performance.
Selection Criteria
Consider visual search and spatial abilities alongside domain-specific testing when recruiting trainees.
Documentation
Implement more detailed documentation practices and incorporate falsification practices in evidence evaluation.
Publications
Capturing Fingerprint Expertise with Protocol Analysis
Applied Cognitive Psychology, 38, e70010
View Paper →The Effect of Fingerprint Expertise on Visual Short-Term Memory
Cognitive Research: Principles and Implications, 9, 14
View Paper →Predicting Expertise in Fingerprint Analysis
Submitted to Journal of Applied Research in Memory and Cognition