Asymptotic Theory of Outlier Detection Algorithms for Linear Time Series Regression Models

Outlier detection algorithms are intimately connected with robust statistics that down‐weight some observations to zero. We define a number of outlier detection algorithms related to the Huber‐skip and least trimmed squares estimators, including the one‐step Huber‐skip estimator and the forward search. Next, we review a recently developed asymptotic theory of these. Finally, we analyse the gauge, the fraction of wrongly detected outliers, for a number of outlier detection algorithms and establish an asymptotic normal and a Poisson theory for the gauge.     

A divergence of opinion: how those involved in child and family social work are responding to the challenges of the Internet and social media

This discussion paper suggests that there is possibly a divergence of opinion taking place within the field of child and family social work and that the stated positions are influencing how practitioners identify and deal with risks and opportunities afforded by the Internet and social media. The suggested divergence is examined and the conclusion drawn is that what is taking place mirrors the fact that the introduction of any new technology inevitably brings with it division and debate. In seeking to understand the reaction to digital technology, consideration is given to a series of wider social discourses on childhood and risk, which includes the controversial notion that the profession is a harbinger of moral panic and that the management of risk has been broadened from child protection to child safety. The discussion paper concludes by calling for child and family social work practitioners to have a balanced debate that needs to be informed not only by current research but also by an open and honest discussion about personal use and an acknowledgement that there will be difficult moral and ethical questions to work through.     

Why Frequency is Not Well Defined for Engineering Systems with Nonexponential Failure Times

Dr. Yellman proposes to define frequency as “a time‐rate of events of a specified type over a particular time interval.” We review why no definition of frequency, including this one, can satisfy both of two conditions: (1) the definition should agree with the ordinary meaning of frequency, such as that less frequent events are less likely to occur than more frequent events, over any particular time interval for which the frequencies of both are defined; and (2) the definition should be applicable not only to exponentially distributed times between (or until) events, but also to some nonexponential (e.g., uniformly distributed) times. We make the simple point that no definition can satisfy (1) and (2) by showing that any definition that determines which of any two uniformly distributed times has the higher “frequency” (or that determines that they have the same “frequency,” if neither is higher) must assign a higher frequency number to the distribution with the lower probability of occurrence over some time intervals. Dr. Yellman's proposed phrase, “time‐rate of events … over a particular time interval” is profoundly ambiguous in such cases, as the instantaneous failure rates vary over an infinitely wide range (e.g., from one to infinity), making it unclear which value is denoted by the phrase “time‐rate of events.”     

Self‐Construal,Career Decision Self‐Efficacy,and Perceived Barriers Predict Mexican American Women's Life Satisfaction

This study used the social cognitive theory of well‐being (SCTW; Lent, 2004 ) to examine the role of career decision self‐efficacy (CDSE), perceived educational barriers, and independent self‐construal on the life satisfaction of 176 Mexican American college women. A 3‐step hierarchical regression analysis indicated that independent self‐construal, CDSE, and fewer perceived educational barriers significantly predicted greater life satisfaction among Mexican American college women above and beyond the influence of socioeconomic status and generational status. These findings are consistent with SCTW and highlight the need for counselors and researchers to be aware of the role that self‐construal, CDSE, and perceived educational barriers can have on Mexican American women's life satisfaction. Implications for practice at the secondary‐school and university levels are discussed.     

Quantifying the Establishment Likelihood of Invasive Alien Species Introductions Through Ports with Application to Honeybees in Australia

The cost of an uncontrolled incursion of invasive alien species (IAS) arising from undetected entry through ports can be substantial, and knowledge of port‐specific risks is needed to help allocate limited surveillance resources. Quantifying the establishment likelihood of such an incursion requires quantifying the ability of a species to enter, establish, and spread. Estimation of the approach rate of IAS into ports provides a measure of likelihood of entry. Data on the approach rate of IAS are typically sparse, and the combinations of risk factors relating to country of origin and port of arrival diverse. This presents challenges to making formal statistical inference on establishment likelihood. Here we demonstrate how these challenges can be overcome with judicious use of mixed‐effects models when estimating the incursion likelihood into Australia of the European (Apis mellifera) and Asian (A. cerana) honeybees, along with the invasive parasites of biosecurity concern they host (e.g., Varroa destructor). Our results demonstrate how skewed the establishment likelihood is, with one‐tenth of the ports accounting for 80% or more of the likelihood for both species. These results have been utilized by biosecurity agencies in the allocation of resources to the surveillance of maritime ports.     

COMMENTARY (12 YEARS ON) ON ‘THE CONTRIBUTION OF OBSERVATION TRAINING TO PROFESSIONAL DEVELOPMENT IN SOCIAL WORK’ BY JUDITH TROWELL AND GILLIAN MILES

This article aims to stimulate discussion about relationships between the lives of professionals and of service users. The idea is that when parallels are explored and developed, power dynamics between professionals and social workers are reduced, the quality of interaction and work with service users can be improved, and professionals can also be helped in overcoming difficulties in their own lives. I start with an outline of my own personal background and highlight my development throughout, including my emerging identity as a Buddhist. I discuss a case study involving ‘Sally’ and her family and our work together while I was a social work assistant in a Children and Family's team. I try to show the interconnections between the different difficulties that we faced and how that informed my work. I look at some of the benefits, pitfalls and boundaries of working from the point of view that service user and professional are both working to overcome their problems. I also interweave interactions I had at the time with Carlos, a drug user friend in a crisis and the impact he had on me. Because I include my own situation I have called this article a ‘case experience’.

Throughout I refer to Buddhist and psychoanalytic thinking and particularly to agreement between the two around ideas that inner‐resistance is the main barrier to personal evolution. I argue that faith is the key to unlocking resistance, and that faith should be understood as the development of a belief within people that they are able to progress rather than be destroyed in the face of inevitable problems.     

Model Checks in Inverse Regression Models with Convolution‐Type Operators

Abstract. We consider the problem of testing parametric assumptions in an inverse regression model with a convolution‐type operator. An L ₂ ‐type goodness‐of‐fit test is proposed which compares the distance between a parametric and a non‐parametric estimate of the regression function. Asymptotic normality of the corresponding test statistic is shown under the null hypothesis and under a general non‐parametric alternative with different rates of convergence in both cases. The feasibility of the proposed test is demonstrated by means of a small simulation study. In particular, the power of the test against certain types of alternative is investigated. Finally, an empirical example is provided, in which the proposed methods are applied to the determination of the shape of the luminosity profile of the elliptical galaxy NGC 5017.     

The Common Assessment Framework form 9 years on: a creative process

Legislation within England states that local authorities should provide services for all those families in need. However, research has identified that regardless of the introduction of strategies to identify need and enhance family support, ongoing barriers to services adhere. Taking a social constructionist approach, this study explored professionals' experiences of the use of the Common Assessment Framework form. Data were collected in four different local authorities in two phases. Forty‐one professionals from a variety of agencies took part in semi‐structured interviews. Data were analyzed thematically. Findings demonstrate that the professionals experienced difficulties in working through the Common Assessment Framework process, for example, in completing the form and engaging families. This situation led to the more experienced and knowledgeable professionals utilising creative ways to successfully navigate the ‘referral process’. Such creative working practices included the terminology used to complete the form and how the process was ‘sold’ to parents, so that they could be in a better position to engage parents and complete the Common Assessment Framework form. Because of this, more experienced professionals seem to be able to accelerate the referral process in order to access much needed support services for children and young people.     

Good Friendships among Children: A Theoretical and Empirical Investigation

Ethical dimensions of friendship have rarely been explicitly addressed as aspects of friendship quality in studies of children's peer relationships. This study identifies aspects of moral virtue significant for friendship, as a basis for empirically investigating the role of ethical qualities in children's friendship assessments and aspirations. We introduce a eudaimonic conception of friendship quality, identify aspects of moral virtue foundational to such quality, review and contest some grounds on which children have been regarded as not mature enough to have friendships that require virtue, and report a qualitative study of the friendship assessments and aspirations of children aged nine and ten (n = 83). In focus group sessions conducted in ten schools across Great Britain, moral qualities figured prominently in children's assessments of friendship quality. The findings provide evidence of children having friendships exhibiting mutual respect, support, and valuing of each other's good character.     

Acculturation and adaptation of first‐ and second‐generation South Asians in Hong Kong

This study investigates the experiences of psychological and sociocultural adaptation among 404 first‐ and second‐generation South Asian immigrants in Hong Kong. Results indicate that for first‐generation immigrants, lack of host language fluency, fewer contacts and friendships with host members, the strategy of marginalisation, and perceived discrimination are all related to higher psychological distress, lower self‐esteem and less competence in sociocultural adaptation. For second‐generation individuals, although they reported higher knowledge of the host language and higher preferences the for assimilation strategy, the levels of psychological distress were higher compared with the first‐generation group. An interesting finding of this study is the preference for the marginalisation strategy as opposed to the assimilation and/or separation strategy. The findings of this study highlight the importance of considering the unique experiences of the second generation in order to further our understanding of immigration and acculturation processes.