Theoretical vs. empirical discriminability:the application of ROC methods to eyewitness identification

Abstract ᅟ Receiver operating characteristic (ROC) analysis was introduced to the field of eyewitness identification 5 years ago. Since that time, it has been both influential and controversial, and the debate has raised an issue about measuring discriminability that is rarely considered. The issue concerns the distinction between empirical discriminability (measured by area under the ROC curve) vs. underlying/theoretical discriminability (measured by d’ or variants of it). Under most circumstances, the two measures will agree about a difference between two conditions in terms of discriminability. However, it is possible for them to disagree, and that fact can lead to confusion about which condition actually yields higher discriminability. For example, if the two conditions have implications for real-world practice (e.g., a comparison of competing lineup formats), should a policymaker rely on the area-under-the-curve measure or the theory-based measure? Here, we illustrate the fact that a given empirical ROC yields as many underlying discriminability measures as there are theories that one is willing to take seriously. No matter which theory is correct, for practical purposes, the singular area-under-the-curve measure best identifies the diagnostically superior procedure. For that reason, area under the ROC curve informs policy in a way that underlying theoretical discriminability never can. At the same time, theoretical measures of discriminability are equally important, but for a different reason. Without an adequate theoretical understanding of the relevant task, the field will be in no position to enhance empirical discriminability

Rethinking microaggressions and anti-social behaviour against LGBTIQ+ youth

Purpose - The purpose of this paper is to further the understanding of experiences of anti-social behaviour in LGBTIQ+ youth in university settings. Design/methodology/approach - The discussion reflects on qualitative interviews with LGBTIQ+ young people studying at university (n = 16) exploring their experiences of anti-social behaviour including harassment, bullying and victimisation in tertiary settings. Findings - The findings demonstrate that attention should be paid to the complex nature of anti-social behaviour. In particular, LGBTIQ+ youth documented experiences of microaggressions perpetrated by other members of the LGBTIQ+ community. Using the taxonomy of anti-social behaviour against LGBTIQ+ people developed by Nadal et al. (2010, 2011), the authors build on literature that understands microaggressions against LGBTIQ+ people as a result of heterosexism, to address previously unexplored microaggressions perpetrated by other LGBTIQ+ people. Research limitations/implications - Future research could seek a larger sample of participants from a range of universities, as campus climate may influence the experiences and microaggressions perpetrated. Practical implications - Individuals within the LGBTIQ+ community also perpetrate microaggressions against LGBTIQ+ people, including individuals with the same sexual orientation and gender identity as the victim. Those seeking to respond to microaggressions need to attune their attention to this source of anti-social behaviour. Originality/value - Previous research has focused on microaggressions and hate crimes perpetrated by non-LGBTIQ+ individuals. This research indicates the existence of microaggressions perpetrated by LGBTIQ+ community members against other LGBTIQ+ persons. The theoretical taxonomy of sexual orientation and transgender microaggressions is expanded to address LGBTIQ+ perpetrated anti-social behaviour. © Emerald Group Publishing Limited