Modeling the effects of combining diverse software fault detection techniques

The software engineering literature contains many studies of the efficacy of fault finding techniques. Few of these, however, consider what happens when several different techniques are used together. We show that the effectiveness of such multitechnique approaches depends upon quite subtle interplay between their individual efficacies and dependence between them. The modelling tool we use to study this problem is closely related to earlier work on software design diversity. The earliest of these results showed that, under quite plausible assumptions, it would be unreasonable even to expect software versions that were developed ‘truly independently’ to fail independently of one another. The key idea here was a ‘difficulty function’ over the input space. Later work extended these ideas to introduce a notion of ‘forced’ diversity, in which it became possible to obtain system failure behaviour better even than could be expected if the versions failed independently. In this paper we show that many of these results for design diversity have counterparts in diverse fault detection in a single software version. We define measures of fault finding effectiveness, and of diversity, and show how these might be used to give guidance for the optimal application of different fault finding procedures to a particular program. We show that the effects upon reliability of repeated applications of a particular fault finding procedure are not statistically independent - in fact such an incorrect assumption of independence will always give results that are too optimistic. For diverse fault finding procedures, on the other hand, things are different: here it is possible for effectiveness to be even greater than it would be under an assumption of statistical independence. We show that diversity of fault finding procedures is, in a precisely defined way, ‘a good thing’, and should be applied as widely as possible. The new model and its results are illustrated using some data from an experimental investigation into diverse fault finding on a railway signalling application

Attitudes to legal authority in adulthood: inter-individual differences and intra-individual stability

This paper considers whether and how attitudes towards legal authority change over time in the British adult population. We apply latent trajectory and autoregressive models using the 1996, 2000 and 2012 sweeps of the British Cohort Study of 1970; after controlling for gender, education, occupational social class, interest in politics and religion, we found that from the age of 26 to the age of 42, the cohort becomes more liberal regarding obedience to the law, the death penalty and stiffer sentencing, but more authoritarian regarding censorship; moreover, individual-level characteristics are associated with inter-individual differences over time, in particular: as occupational social class and level of education increase, attitudes tend to be more liberal; interest in politics is positively associated with less authoritarian attitudes; those who define themselves as non-religious tend to be more liberal; the effect of gender varies by attitude: females are more authoritarian towards censorship, but more liberal regarding capital punishment and stiffer sentencing. The analyses reported here give support at the micro level to the hypotheses of relative consistency and stability of attitudes to legal authority, as well providing evidence for important social cleavages

Understanding ethnic inequalities in hearing health in the UK: a cross-sectional study of the link between language proficiency and performance on the Digit Triplet Test

Introduction Research using the UK Biobank data has shown ethnic inequalities in hearing health; however, the hearing test used may exhibit a disadvantage for non-native language speakers. Objectives To validate the results of the UK Biobank hearing test (Digit Triplet Test, DTT) against self-reported measures of hearing in the dataset and create classifications of hearing health. To observe if language proficiency and migration age have the same effect on hearing health classification as on the DTT in isolation. Our hypothesis is that language proficiency acts differently on the DTT, demonstrating that the DTT is biased for non-native speakers of English. Design Latent classes representing profiles of hearing health were identified from the available hearing measures. Factors associated with class membership were tested using multinomial logistic regression models. Ethnicity was defined as (1) White, native English-speaking, (2) ethnic minority, arrived in the UK aged 12. Participants The UK Biobank participants with valid hearing test results and associated covariates (N=151 268). Outcome measures DTT score, self-reported hearing difficulty, self-reported hearing difficulty in noise and hearing aid use. Results Three classes of hearing health were found: ‘normal’, ‘generally poor’ and ‘only subjectively poor’. In a model adjusting for known confounders of hearing loss, a poor or insufficient hearing test result was less likely for those with better language (OR 0.69, 95% CI 0.65 to 0.74) or numerical ability (OR 0.71, 95% CI 0.67 to 0.75) but more likely for those having migrated aged >12 (OR 3.85, 95% CI 3.64 to 4.07). Conclusions The DTT showed evidence of bias, having greater dependence on language ability and migration age than other hearing indicators. Designers of future surveys and hearing screening applications may wish to consider the limitations of speech-in-noise tests in evaluating hearing acuity for populations that include non-native speakers

Negative cognition, affect, metacognition and dimensions of paranoia in people at ultra-high risk of psychosis: a multi-level modelling analysis

Background: Paranoia is one of the commonest symptoms of psychosis but has rarely been studied in a population at risk of developing psychosis. Based on existing theoretical models, including the proposed distinction between ‘poor me’ and ‘bad me’ paranoia, we aimed to test specific predictions about associations between negative cognition, metacognitive beliefs and negative emotions and paranoid ideation and the belief that persecution is deserved (deservedness). Method: We used data from 117 participants from the Early Detection and Intervention Evaluation for people at risk of psychosis (EDIE-2) trial of cognitive–behaviour therapy, comparing them with samples of psychiatric in-patients and healthy students from a previous study. Multi-level modelling was utilized to examine predictors of both paranoia and deservedness, with post-hoc planned comparisons conducted to test whether person-level predictor variables were associated differentially with paranoia or with deservedness. Results: Our sample of at-risk mental state participants was not as paranoid, but reported higher levels of ‘bad-me’ deservedness, compared with psychiatric in-patients. We found several predictors of paranoia and deservedness. Negative beliefs about self were related to deservedness but not paranoia, whereas negative beliefs about others were positively related to paranoia but negatively with deservedness. Both depression and negative metacognitive beliefs about paranoid thinking were specifically related to paranoia but not deservedness. Conclusions: This study provides evidence for the role of negative cognition, metacognition and negative affect in the development of paranoid beliefs, which has implications for psychological interventions and our understanding of psychosis

Why does relative deprivation affect mental health? The role of justice, trust and social rank in psychological wellbeing and paranoid ideation

Purpose – Relative deprivation is associated with poor mental health but the mechanisms responsible have rarely been studied. The purpose of this paper is to hypothesize that childhood perceived relative deprivation (PRD) would be linked to sub-syndromal psychotic symptoms and poor wellbeing via beliefs about justice, trust and social rank. Design/methodology/approach – In total, 683 undergraduate students were administered measures of childhood PRD, hallucination-proneness, paranoia and wellbeing and measures of trust, social rank and beliefs about justice. A subsample supplied childhood address data. Multiple mediation analysis was used to assess pathways from childhood experiences to outcomes. Findings – Childhood PRD was associated with all three outcomes. The relationship between PRD and paranoia was fully mediated by perceptions that the world is unjust for the self and low social rank. The same variables mediated the relationship between PRD and poor wellbeing. There were no significant mediators of the relationship between PRD and hallucination-proneness. Research limitations/implications – Although our outcome measures have been validated with student samples, it may not be representative. The study is cross-sectional with a retrospective measure of PRD, although similar results were found using childhood addresses to infer objective deprivation. Further studies are required using prospective measures and patient samples. Social implications – Social circumstances that promote feelings of low social worth and injustice may confer risk of poor psychological outcome. Ameliorating these circumstances may improve population mental health. Originality/value – Improvements in public mental health will require an understanding of the mechanisms linking adversity to poor outcomes. This paper explores some probable mechanisms which have hitherto been neglected

Inter- and intra-generational social mobility effects on subjective well-being – Evidence from mainland China

This paper contributes to the literature on well-being research by showing the distinct impacts of inter- and intra-generational social mobility on subjective well-being in mainland China. Based on the China General Social Surveys of 2006, we used diagonal reference modelling and other regression methods to assess the effects of social mobility on well-being. We found that well-being was associated with changes in class positions. In both inter- and intra-generational mobility trajectories, moving upward into a higher position was beneficial for people's well-being whereas different consequences were found for downward mobility: in the case of intergenerational mobility, downward mobility into the manual class did not have a marked effect on people's well-being as the downwardly mobile from privileged backgrounds held the prospect of counter-mobility at early career stages and inherited valuable resources; but downward mobility in one's own career life was rather detrimental to subjective well-being, as the downwardly mobile had to bear not only the material disadvantages found in the lower position, but also the psychological effects ensuing from the downward trajectory. We conclude that while those experiencing downward intergenerational mobility may resort to family advantages to help maintain their well-being levels, a similar trajectory in one's own career life may have a direct negative consequence

A mental health promotion approach to reducing discrimination about psychosis in teenagers

Aim: To examine the effectiveness of a psychosocial mental health promotion workshop, involving an ex‐service‐user researcher, in reducing discrimination about psychosis in teenagers. Hypothesis: Pupils in the intervention condition will express less discrimination about a man characterised as having experienced psychosis immediately after the workshop and at follow‐up, compared with pupils in the control condition. Method: A cluster randomised trial was carried out in order to take into account the effect of class group. Ninety‐two pupils participated at baseline; 43 pupils were exposed to the intervention and 49 pupils formed the control group. Pupils completed demographic information, questions about their familiarity with people with mental health problems and a questionnaire examining discrimination about psychosis. Results: Multi‐level modelling was used to analyse the results. Discrimination scores in the intervention group reduced significantly more than the control group immediately after the intervention. This effect was not sustained at 10‐week follow‐up. Brief qualitative feedback from pupils exposed to the intervention indicated that 70% considered the testimonial from the ex‐service‐user researcher to be the most useful. Conclusion: A short psychosocial intervention involving a testimonial from an ex‐service user can lead to small but significant reductions in teenagers' discrimination about psychosis immediately after the intervention

Investigating ethnic inequalities in hearing aid use in England and Wales: a cross-sectional study

Objective To establish whether ethnic inequalities exist in levels of self-reported hearing difficulty and hearing aid use among middle-aged adults. Design Cross-sectional data from the UK Biobank resource. Study sample 164,460 participants aged 40–69 who answered hearing questions at an assessment centre in England or Wales. Results After taking into account objectively assessed hearing performance and a corresponding correction for bias in non-native English speakers, as well as a range of correlates including demographic, socioeconomic, and health factors, there were lower levels of hearing aid use for people from Black African (OR 0.36, 95% CI 0.17–0.77), Black Caribbean (OR 0.38, 95% CI 0.22–0.65) and Indian (OR 0.60, 95% CI 0.41–0.86) ethnic groups, compared to the White British or Irish group. Men from most ethnic minority groups and women from Black African, Black Caribbean and Indian groups were less likely to report hearing difficulty than their White British or Irish counterparts. Conclusions For equivalent levels of hearing loss, the use of hearing aids is lower among ethnic minority groups. Inequalities are partly due to lower levels of self-reported hearing difficulty among minority groups. However, even when self-reported hearing difficulty is considered, hearing aid use remains lower among many ethnic minority groups