In 2015 and 2016 the Central Unit of the Dutch National Police created and submitted 21 cartridge case comparison tests as real cases to the Netherlands Forensic Institute (NFI), under supervision... Show moreIn 2015 and 2016 the Central Unit of the Dutch National Police created and submitted 21 cartridge case comparison tests as real cases to the Netherlands Forensic Institute (NFI), under supervision of the University of Twente (UT). A total of 53 conclusions were drawn in these 21 tests. For 31 conclusions the underlying ground truth was ‘positive’, in the sense that it addressed a cluster of cartridge cases that was fired from the same firearm. For 22 conclusions the ground truth was ‘negative’, in the sense that the cartridge cases were fired from different firearms. In none of the conclusions, resulting from examinations under casework conditions, misleading evidence was reported. All conclusions supported the hypothesis reflecting the ground truth. This article discusses the design and results of the tests in more detail. Show less
We would like to respond to the recent paper “Understanding forensic expert evaluative evidence: A study of the perception of verbal expressions of the strength of evidence”, by Arscott et al.. We... Show moreWe would like to respond to the recent paper “Understanding forensic expert evaluative evidence: A study of the perception of verbal expressions of the strength of evidence”, by Arscott et al.. We agree that a verbal expression of the strength of evidence can be interpreted in varying ways. Not only by the people that read them, but also by those that express them. It is also possible that different verbal expressions are interpreted in the same way by different readers or reporting scientists. This is the reason that the Association of Forensic Science Providers (AFSP) and the European Network of Forensic Science Institutes (ENFSI) have published guidelines that call for forensic institutes to provide verbal scales and numerically define the verbal expressions therein. This, at least formally, solves the issue of the perception of intended strength of evidence. Show less
Managing context information in forensic casework aims to minimize task-irrelevant information while maximizing the task-relevant information that reaches the examiner. A design and implementation... Show moreManaging context information in forensic casework aims to minimize task-irrelevant information while maximizing the task-relevant information that reaches the examiner. A design and implementation of context information management (CIM) is described for forensic firearms examination. Guided by a taxonomy of different sources of context information, a flow-chart was constructed that specifies the process of casework examination and context information management. Due to the risk of bias, another examiner may need to be involved when context information management is unsuccessful. Application of context information management does not make a subjective examination objective, but can limit the risks of bias with a minimal investment of time and resources. Show less
Previous studies on the counsellees' perception of DNA test results did not clarify whether counsellees were asked about their recollections or interpretations, and focused only on patients' own... Show morePrevious studies on the counsellees' perception of DNA test results did not clarify whether counsellees were asked about their recollections or interpretations, and focused only on patients' own risks and not on the likelihood that cancer is heritable in the family. We tested differences and correlations of four perception aspects: recollections and interpretations of both cancer risks and heredity likelihood. In a retrospective study, women tested for BRCA1/2 on average, 5 years ago, completed questionnaires about their perception. Participants had received an unclassified variant (n = 76), uninformative (n = 76) or pathogenic mutation (n = 51) result in BRCA1/2. Analyses included t-tests, correlations and structural equation modelling. The counsellees' perception showed to consist of four distinctive phenomena: recollections and interpretations of cancer risks and of heredity likelihood. This distinctiveness was suggested by significant differences between these perception variables. Moderate to strong correlations were found between these variables, suggesting that these differences between variables were consistent. The relationships between these variables were not influenced by actually communicated DNA test results, sociodemographics, medical and pedigree information, or framing of cancer risk questions. The largest differences between recollections and interpretations were found in the unclassified variant group and the smallest in uninformatives. Cancer risks and heredity likelihood correlated least in the pathogenic mutation group. Communication of ambiguous genetic information enlarged the differences. To understand the counsellees' perception of genetic counselling, researchers should study recollections and interpretations of cancer risks and heredity likelihood. Genetic counsellors should explicitly address the counsellees' recollections and interpretations, and be aware of possible inaccuracies. Show less
Vos J, Oosterwijk JC, Gómez-García E, Menko FH, Jansen AM, Stoel RD, van Asperen CJ, Tibben A, Stiggelbout AM. Perceiving cancer-risks and heredity-likelihood in genetic-counseling: how counselees... Show moreVos J, Oosterwijk JC, Gómez-García E, Menko FH, Jansen AM, Stoel RD, van Asperen CJ, Tibben A, Stiggelbout AM. Perceiving cancer-risks and heredity-likelihood in genetic-counseling: how counselees recall and interpret BRCA 1/2-test results. Previous studies on the counsellees' perception of DNA test results did not clarify whether counsellees were asked about their recollections or interpretations, and focused only on patients' own risks and not on the likelihood that cancer is heritable in the family. We tested differences and correlations of four perception aspects: recollections and interpretations of both cancer risks and heredity likelihood. In a retrospective study, women tested for BRCA1/2 on average, 5 years ago, completed questionnaires about their perception. Participants had received an unclassified variant (n = 76), uninformative (n = 76) or pathogenic mutation (n = 51) result in BRCA1/2. Analyses included t-tests, correlations and structural equation modelling. The counsellees' perception showed to consist of four distinctive phenomena: recollections and interpretations of cancer risks and of heredity likelihood. This distinctiveness was suggested by significant differences between these perception variables. Moderate to strong correlations were found between these variables, suggesting that these differences between variables were consistent. The relationships between these variables were not influenced by actually communicated DNA test results, sociodemographics, medical and pedigree information, or framing of cancer risk questions. The largest differences between recollections and interpretations were found in the unclassified variant group and the smallest in uninformatives. Cancer risks and heredity likelihood correlated least in the pathogenic mutation group. Communication of ambiguous genetic information enlarged the differences. To understand the counsellees' perception of genetic counselling, researchers should study recollections and interpretations of cancer risks and heredity likelihood. Genetic counsellors should explicitly address the counsellees' recollections and interpretations, and be aware of possible inaccuracies. Show less
