Error mitigation in forensic handwriting examination: the examiner's perspective

Like other pattern recognition disciplines, forensic handwriting examination relies on various human factors. Expert opinions in the field are based on visual analysis and comparison, and the evaluation of findings is generally conducted without reference to tabulated data. This high level of subjectivity may contribute to bias and error in the examination process. In this paper, we draw on our research and practical experience to discuss error mitigation on several levels, addressing both aspects of quality management and the individual responsibility of examiners. Because a good understanding of the concept of error is needed to communicate appropriately about this subject, definitions of error-related concepts are provided. We consider contextual information management essential to reduce the potential for cognitive bias in casework. To ensure completeness of findings and avoid omission errors, the use of checklists during a forensic handwriting examination is encouraged, and an exemplary checklist incorporating all the examination steps is provided. We consider the use of a logical reasoning approach to evaluate findings an important step towards robustness and transparency in the examiner's report. An independent, blinded peer review of the examination is recommended as a further key step in error mitigation. Regular participation in testing programmes and continuous training and education are essential to maintaining and improving competency at both individual and organizational levels. Finally, developments in the form of tabulated data and the use of algorithms are considered useful ways of increasing objectivity in the field and minimizing human error.