Abstract:
The issues of validity and reliability are important in forensic
science. Within the likelihood-ratio framework for the
evaluation of forensic evidence, the log-likelihood-ratio cost
(Cllr) has been applied as an appropriate metric for evaluating
the accuracy of the output of a forensic-voice-comparison
system, but there has been little research on developing a
quantitative metric of precision. The present paper describes
two procedures for estimating the precision of the output of a
forensic-comparison system, a non-parametric estimate and a
parametric estimate of its 95% credible interval. The
procedures are applied to estimate the precision of a basic
automatic forensic-voice-comparison system presented with
different amounts of questioned-speaker data. The importance
of considering precision is discussed.
