Estimators in capture–recapture studies with two sources

This paper investigates the applications of capture–recapture methods to human populations. Capture–recapture methods are commonly used in estimating the size of wildlife populations but can also be used in epidemiology and social sciences, for estimating prevalence of a particular disease or the size of the homeless population in a certain area. Here we focus on estimating the prevalence of infectious diseases. Several estimators of population size are considered: the Lincoln–Petersen estimator and its modified version, the Chapman estimator, Chao’s lower bound estimator, the Zelterman’s estimator, McKendrick’s moment estimator and the maximum likelihood estimator. In order to evaluate these estimators, they are applied to real, three-source, capture-recapture data. By conditioning on each of the sources of three source data, we have been able to compare the estimators with the true value that they are estimating. The Chapman and Chao estimators were compared in terms of their relative bias. A variance formula derived through conditioning is suggested for Chao’s estimator, and normal 95% confidence intervals are calculated for this and the Chapman estimator. We then compare the coverage of the respective confidence intervals. Furthermore, a simulation study is included to compare Chao’s and Chapman’s estimator. Results indicate that Chao’s estimator is less biased than Chapman’s estimator unless both sources are independent. Chao’s estimator has also the smaller mean squared error. Finally, the implications and limitations of the above methods are discussed, with suggestions for further development.

Estimators in capture-recapture studies with two sources

This paper investigates the applications of capture-recapture methods to human populations. Capture-recapture methods are commonly used in estimating the size of wildlife populations but can also be used in epidemiology and social sciences, for estimating prevalence of a particular disease or the size of the homeless population in a certain area. Here we focus on estimating the prevalence of infectious diseases. Several estimators of population size are considered: the Lincoln-Petersen estimator and its modified version, the Chapman estimator, Chao's lower bound estimator, the Zelterman's estimator, McKendrick's moment estimator and the maximum likelihood estimator. In order to evaluate these estimators, they are applied to real, three-source, capture-recapture data. By conditioning on each of the sources of three source data, we have been able to compare the estimators with the true value that they are estimating. The Chapman and Chao estimators were compared in terms of their relative bias. A variance formula derived through conditioning is suggested for Chao's estimator, and normal 95% confidence intervals are calculated for this and the Chapman estimator. We then compare the coverage of the respective confidence intervals. Furthermore, a simulation study is included to compare Chao's and Chapman's estimator. Results indicate that Chao's estimator is less biased than Chapman's estimator unless both sources are independent. Chao's estimator has also the smaller mean squared error. Finally, the implications and limitations of the above methods are discussed, with suggestions for further development.

Confucius, constructivism and the impact of continuing professional development on teachers of English in China

In this article we explore issues around the sustainability and appropriateness of professional development for secondary teachers of English in China offered by overseas providers from the perspective of teachers who completed courses at the University of Reading between 2003 and 2010. We start by offering an overview of English teaching in China. We then describe the collection and analysis of interviews and focus groups discussions involving former participants, their teaching colleagues and senior management, as well as classroom observation. Evidence is presented for changes in teachers’ philosophies of education directly attributable to participation in the courses; for improved teacher competencies (linguistic, cultural and pedagogical) in the classroom; and for the ways in which returnees are undertaking new roles and responsibilities which exploit their new understandings. Finally, we discuss the implications of these findings for both providers and sponsors of CPD for English language teachers. We conclude that the recognition of English as an essential element in the modernisation of China, together with the growing awareness of the weaknesses of traditional approaches to the teaching of the language, has opened up new spaces for dialogue concerning pedagogy and professional practice. It is clearly important, however, that new approaches to the teaching of English are presented in a way which allows teachers to decide which elements should be incorporated into their teaching and how.

History education in comprehensive schools: using school level data to interpret national patterns

This paper reports the findings from two large scale national on-line surveys carried out in 2009 and 2010, which explored the state of history teaching in English secondary schools. Large variation in provision was identified within comprehensive schools in response to national policy decisions and initiatives. Using the data from the surveys and school level data that is publicly available, this study examines situated factors, particularly the nature of the school intake, the numbers of pupils with special educational needs and the socio-economic status of the area surrounding the school, and the impact these have on the provision of history education. The findings show that there is a growing divide between those students that have access to the ‘powerful knowledge’, provided by subjects like history, and those that do not.

L2 performance and context of language learning: a comparative study of learners in Tehran and London

The importance of learning context has stirred debates in the field of second language acquisition over the past two decades since studying a second language (L2) abroad is believed to provide authentic opportunities that facilitate L2 acquisition and development. The present paper examines whether language performance of learners studying English in a formal language classroom context at home (AH) is different from performance of learners who study English abroad (SA) where they would have to use English for a range of communicative purposes. The data for this comparative study is part of a larger corpus of L2 performance of 100 learners of English, 60 in Tehran and 40 in London, on four oral narrative tasks. The two groups’ performances are compared on a range of different measures of fluency, accuracy, syntactic complexity and lexical diversity. The results of the analyses indicate that learners in the two contexts are very similar with respect to the grammatical accuracy and aspects of the oral fluency of their performance. However, the SA group appears to have benefited from living and studying abroad in producing language of higher syntactic complexity and lexical diversity. These results have significant implications for language teaching in AH contexts.

Where have all the linguists gone? The position of Linguistics in British German Studies from the mid-19th century until 2000

Retrospectively, Linguistics - understood as a scientific study of language - has been an important part of British German Studies. In fact, the establishment of modern language as academic disciplines in the UK is closely related to the Germanic philology and the interest in the history, and structure of languages. However, over the last few decades, a demise of Linguistics in the departments of modern languages has been observed. The aim of this paper is to survey the position of linguistic research and teaching in the discipline of German Studies in the UK. To begin with, I will give a brief account of the history of linguistic/ language studies in the discipline. Subsequently, the current position of Linguistics in research and teaching will be scrutinised. Finally, this paper will discuss the importance of linguistic insights for the discipline of German Studies, with particular reference to teaching.

Planning for development or decline? Education policy for Chinese language in Singapore

This article examines how political discourse, language ideologies, recent Chinese curriculum reforms, and their representations in the media are inextricably related. Using the Speak Mandarin Campaign as background for the inquiry, I focus on textual features of the various media sources, TV advertisements, campaign slogans, official speeches, and newspaper excerpts to illuminate the status and changing role of the Chinese language in Singapore’s sociocultural, economic, and political development. Using critical discourse analysis as an analytical framework, I examine the contradictory ideologies that underpin the government’s language policies and planning activities. On the one hand, the government emphasizes the cultural and economic values of the Chinese language; on the other hand, government schools teach Chinese as a subject. In particular, the recent reforms in Chinese language curriculum have arguably further diluted the content of teaching. In addition I point out how conflicting ideologies behind language policies can lead to cultural confusion and educational uncertainty. These mixed messages make it difficult for schools to offer a consistent language education curriculum that will help students appreciate the value, be it economic, cultural or educational, of the Chinese language.

MA TEFL programmes in Iran: change in a globalised era

This chapter is a modest attempt to investigate how MA TEFL programmes in Iran are changing in a globalised world. Our previous research in this area (Hasrati & Tavakoli, in print; Tavakoli & Hasrati, in preparation) has shown how MAs in English Language Teaching programmes are developing in Anglophone countries, but little or no research has been conducted to study changes in MA TEFL programmes in Iran. In what follows, we will first introduce MA TEFL programmes in Iran, before presenting and discussing different definitions of globalisation. We will then explain how we collected the data for this study and report our findings, making comparisons with the other contexts when appropriate. We will conclude by elaborating on possible extensions of this study in similar contexts.

University teaching: recognition and reward

Teaching in universities has increased in importance in recent years which, in part, is a consequence of the change in funding of universities from block grants to student tuition fees. Various initiatives have been made which serve to raise the profile of teaching and give it greater recognition. It is also important that teaching is recognised even more fully and widely, and crucially that it is rewarded accordingly. We propose a mechanism for recognising and rewarding university teaching that is based on a review process that is supported by documented evidence whose outcomes can be fed into performance and development reviews, and used to inform decisions about reward and promotion, as well as the review of probationary status where appropriate.

Complexity and anisotropy in host morphology make populations less susceptible to epidemic outbreaks

One of the challenges in epidemiology is to account for the complex morphological structure of hosts such as plant roots, crop fields, farms, cells, animal habitats and social networks, when the transmission of infection occurs between contiguous hosts. Morphological complexity brings an inherent heterogeneity in populations and affects the dynamics of pathogen spread in such systems. We have analysed the influence of realistically complex host morphology on the threshold for invasion and epidemic outbreak in an SIR (susceptible-infected-recovered) epidemiological model. We show that disorder expressed in the host morphology and anisotropy reduces the probability of epidemic outbreak and thus makes the system more resistant to epidemic outbreaks. We obtain general analytical estimates for minimally safe bounds for an invasion threshold and then illustrate their validity by considering an example of host data for branching hosts (salamander retinal ganglion cells). Several spatial arrangements of hosts with different degrees of heterogeneity have been considered in order to separately analyse the role of shape complexity and anisotropy in the host population. The estimates for invasion threshold are linked to morphological characteristics of the hosts that can be used for determining the threshold for invasion in practical applications.

Why Implementing History and Philosophy in School Science Education is a Challenge: An Analysis of Obstacles

Teaching and learning with history and philosophy of science (HPS) has been, and continues to be, supported by science educators. While science education standards documents in many countries also stress the importance of teaching and learning with HPS, the approach still suffers from ineffective implementation in school science teaching. In order to better understand this problem, an analysis of the obstacles of implementing HPS into classrooms was undertaken. The obstacles taken into account were structured in four groups: 1. culture of teaching physics, 2. teachers` skills, epistemological and didactical attitudes and beliefs, 3. institutional framework of science teaching, and 4. textbooks as fundamental didactical support. Implications for more effective implementation of HPS are presented, taking the social nature of educational systems into account.

Vocational English in policy and practice

The aim of this licentiate thesis is to examine how, and in what ways, vocational English is a part of English language teaching in the Building and Construc­tion Programme in Sweden, and what the influences are for such pedagogy. The main research question is how policy documents relate to the views of teachers and their educational practice regarding vocational English. The study consists of two parts: a textual policy analysis of the three latest upper secondary school reforms in Sweden (Lgy 70, Lpf 94, and Gy 2011), and semi-structured interviews with practicing English teachers in the Building and Construction Programme. The interviews are categorised by using Spradley’s (1979) semantic relationships and taxonomies. Balls’ (Ball, 1993) and Ozga’s (1990; 2000) concept of policy enactment is used in the analysis as well as Bernstein’s (1990; 2000) theoretical framework of classification, framing, and horizontal and vertical discourse. The results show that five of the six teachers in the interviews work with vocational English in some way. The study also shows that there is a distinct gap between policy and practice. Several of the teachers have the notion that they are supposed to work with vocational English and that it must be written down in policy somewhere. The greatest influence on the teaching for these teachers are their students, either indirectly or directly. Further, the study shows that different frame factors such as time poverty hinders the teachers from reading policy texts and cooperating with the vocational teachers in the Building and Construction Programme.

Children’s Literature and English Teaching – Swedish Teachers’ Methods and Attitudes

This study investigates how primary school teachers of grades F-3 pupils in a number of sample schools in Sweden use children’s literature and other methods to enhance their teaching of English. The study explores the attitudes of these teachers’ to using English children’s literature as a teaching tool to promote language development in their pupils, focusing on vocabulary. An empirical questionnaire study was carried out including a total of twenty-three respondents from seven schools in a Stockholm suburb. The respondents are all working teachers with experience of teaching English to young learners, particularly in grades F-3. This study contributes with new knowledge about the often-recommended use of children’s literature as a method for teaching English to young learners, connecting international research with empirical data from the Swedish context. While the results suggest that the majority of the respondents are positive to using children’s literature in their teaching and regularly do so, many of them feel that it is somewhat difficult to find relevant materials to plan, implement and evaluate lessons within the allocated time-frame. Based on these results, further research about how to create more effective ways of using children’s literature as a method for English vocabulary teaching in Swedish schools is recommended.