99 research outputs found

    An international investigation of forensic speaker comparison practices

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    The results of the first international survey on forensic speaker comparison practices are presented in this paper. Thirty-four experts from 13 countries and 5 continents responded to a series of questions concerning their practices in casework and which features they found to be useful speaker discriminants. Despite the responses revealing some prominent trends, there is wide variation in methodology, importance assigned to particular speech features, and choice of framework for expressing conclusions

    Evidence evaluation for discrete data

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    Methods for the evaluation of evidence in the form of measurements by means of the likelihood ratio are becoming more widespread. There is a paucity of methods for the evaluation of evidence in the form of counts by means of the likelihood ratio. The outline of an empirical method based on relative frequencies that takes account of similarity and rarity is described. It is compared with two methods based on an assumption of independence of counts and one assuming dependence between adjacent Bernoulli variables. Examples of their performance are illustrated in the context of a problem in forensic phonetics. There is discussion of the problems particular to the evaluation of evidence for discrete data, with suggestions for further work

    Front-end approaches to the issue of correlations in forensic speaker comparison

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    In likelihood ratio (LR)-based forensic speaker comparison it is essential to consider correlations between parameters to accurately estimate the overall strength of the evidence. Current approaches attempt to deal with correlations after the computation of LRs (back-end processing). This paper explores alternative, front-end techniques, which consider the underlying correlation structure of the raw data. Calibrated LRs were computed for a range of parameters commonly analysed in speaker comparisons. LRs were combined using (1) an assumption of independence, (2) the mean, (3) assumptions from phonetic theory, and (4) empirical correlations in the raw data. System (1), based on an assumption of independence, produced the best validity (Cllr = 0.04). Predictably, overall strength of evidence was also highest for system (1), while strength of evidence was weakest using the mean (2). Both systems (3) and (4) performed well achieving Cllr values of ca. 0.09

    “We don't pronounce our t's around here":Realisations of /t/ in West Yorkshire English

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    Calculating likelihood ratios for forensic speaker comparisons using phonetic and linguistic parameters

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    The research presented in this thesis examines the calculation of numerical likelihood ratios using phonetic and linguistic parameters derived from a corpus of recordings of speakers of Southern Standard British English. The research serves as an investigation into the development of the numerical likelihood ratio as a medium for framing forensic speaker comparison conclusions. The thesis begins by investigating which parameters are claimed to be the most useful speaker discriminants according to expert opinion, and in turn examines four of these ‘selected/valued’ parameters individually in relation to intra- and inter-speaker variation, their capacities as speaker discriminants, and the potential strength of evidence they yield. The four parameters analyzed are articulation rate, fundamental frequency, long-term formant distributions, and the incidence of clicks (velaric ingressive plosives). The final portion of the thesis considers the combination of the four parameters under a numerical likelihood ratio framework in order to provide an overall likelihood ratio. The contributions of this research are threefold. Firstly, the thesis presents for the first time a comprehensive survey of current forensic speaker comparison practices around the world. Secondly, it expands the phonetic literature by providing acoustic and auditory analysis, as well as population statistics, for four phonetic and linguistic parameters that survey participants have identified as effective speaker discriminants. And thirdly, it contributes to the forensic speech science and likelihood ratios for forensics literature by considering what steps can be taken to conceptually align the area of forensic speaker comparison with more developed areas of forensic science (e.g. DNA) by creating a human-based (auditory and acoustic-phonetic) forensic speaker comparison system

    Creating research-ready partnerships: The initial development of seven implementation laboratories to advance cancer control

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    BACKGROUND: In 2019-2020, with National Cancer Institute funding, seven implementation laboratory (I-Lab) partnerships between scientists and stakeholders in \u27real-world\u27 settings working to implement evidence-based interventions were developed within the Implementation Science Centers in Cancer Control (ISC3) consortium. This paper describes and compares approaches to the initial development of seven I-Labs in order to gain an understanding of the development of research partnerships representing various implementation science designs. METHODS: In April-June 2021, members of the ISC3 Implementation Laboratories workgroup interviewed research teams involved in I-Lab development in each center. This cross-sectional study used semi-structured interviews and case-study-based methods to collect and analyze data about I-Lab designs and activities. Interview notes were analyzed to identify a set of comparable domains across sites. These domains served as the framework for seven case descriptions summarizing design decisions and partnership elements across sites. RESULTS: Domains identified from interviews as comparable across sites included engagement of community and clinical I-Lab members in research activities, data sources, engagement methods, dissemination strategies, and health equity. The I-Labs use a variety of research partnership designs to support engagement including participatory research, community-engaged research, and learning health systems of embedded research. Regarding data, I-Labs in which members use common electronic health records (EHRs) leverage these both as a data source and a digital implementation strategy. I-Labs without a shared EHR among partners also leverage other sources for research or surveillance, most commonly qualitative data, surveys, and public health data systems. All seven I-Labs use advisory boards or partnership meetings to engage with members; six use stakeholder interviews and regular communications. Most (70%) tools or methods used to engage I-Lab members such as advisory groups, coalitions, or regular communications, were pre-existing. Think tanks, which two I-Labs developed, represented novel engagement approaches. To disseminate research results, all centers developed web-based products, and most (n = 6) use publications, learning collaboratives, and community forums. Important variations emerged in approaches to health equity, ranging from partnering with members serving historically marginalized populations to the development of novel methods. CONCLUSIONS: The development of the ISC3 implementation laboratories, which represented a variety of research partnership designs, offers the opportunity to advance understanding of how researchers developed and built partnerships to effectively engage stakeholders throughout the cancer control research lifecycle. In future years, we will be able to share lessons learned for the development and sustainment of implementation laboratories

    Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

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    As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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