bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Lexico‐grammatical Features of Korean English Newspapers
Authors: Jung Kyutae , Min Su Jung
Published: March 2003

The aim of this study is to investigate the use of English in English newspapers published in Korea. This paper presents a report on a corpus‐based investigation of the use of English in Korean English newspapers: modals which express meanings associated with volition and prediction; and prepositions which denote spatial relations that are believed to be the result of contact with Korean. The use of computer corpora in this study has the advantage that they can easily be shared and thus subjected to a wider range of studies, avoiding the over‐reliance on intuition found in many approaches. Based on this corpus‐based approach to the use of English, we examine the use of English in Korea and show some aspects of the nativization of English as the result of contact with Korean.
Standards? Dictionaries and their Development in Second Language Learning Contexts
Authors: Pakir Anne
Published: March 2003

This paper focuses on ‘English’ dictionaries and their development in second language learning contexts, taking the perspective that ‘standards’ are usually codified in reference grammars, pronouncing dictionaries and word dictionaries. It begins with a presentation of contemporary discussions of ‘English’ and ‘Englishes’ in Asia, a phenomenon that has come about through the global spread of what is now a truly universal language. With the second diaspora of English (Kachru, 1992), many of the educational institutions in Asia are beginning to feel the tension between rigid and loose canons, and between traditional and emerging norms of language usage. In English as an additional language learning communities, lexical innovation is evident in new canons, and in primary sources of data such as newspapers. How do dictionaries handle such innovations, and become themselves a secondary source? The question may not be an easy one to answer but the discussion leading to it may herald a new dawn in dictionary‐making in Asia.
Black South African English: Where to from here?
Authors: De Klerk Vivian
Published: March 2003

Black South African English is generally regarded as the variety of English commonly used by mother‐tongue speakers of South Africa's indigenous African languages in areas where English is not the language of the majority. This paper explores some of the problems involved in defining this variety, problems such as whether it is a ‘new’ variety of English or a dialect, and problems relating to whose English it is: the English of those learners who have encountered only a smattering of English in informal contexts or the variety of English acquired during formal schooling. The second half of the paper focuses on the possible future of Black South African English (BSAE) against the backdrop of South Africa's new multilingual policy. Reasons for the continued appeal of English are examined, alongside the range of factors influencing the possible future growth of BSAE as a distinct variety. It is argued that South Africans are unlikely ever to be free not to learn English, owing to the huge economic, political and ideological constraints which make the ‘choice’ of English inevitable. The success of current efforts to resist value judgements and recognise the worth of BSAE will depend not only on the goodwill of South Africans, and on the cooperation of all speakers of English, world‐wide, but on the rate at which the variety drifts away from recognised standard forms of English.
Researching Hong Kong English: bibliographical resources
Authors: Bolton Kingsley
Published: March 2003

This paper provides a brief guide to published research relevant to the study of Hong Kong Kong English, together with a selective bibliography. Hong Kong now has a thriving research culture although a substantial proportion of published research has earlier been devoted to applied linguistic and language pedagogy, where the discussion of ‘Hong Kong English’ has frequently been linked to studies of error analysis and interlanguage. The selective bibliography attempts to survey published research in those areas of sociolinguistics and applied linguistics of most relevance to the world Englishes paradigm, and also includes a section listing publications related to Hong Kong creative writing in English. The final section lists extant bibliographies in print and/or available online via the Internet.
Nonlinear Pricing, Redistribution, and Optimal Tax Policy
Authors: Cremer Helmuth , Gahvari Firouz
Published: March 2003

This paper examines the role of nonlinear pricing by public (or regulated) utilities as a redistributive mechanism in presence of an optimal nonlinear income tax. It models an economy with many types of persons who differ in two unobservable characteristics (earning abilities and tastes). We show that nonlinear pricing does have a redistributive role; it is not a substitute for an ill‐designed tax policy. We prove, assuming separable preferences, that a person whose valuation of the public sector output is smaller than the average valuation of the population (all measured at the same consumption bundle) must face a marginal price for the good above its marginal cost. Further assuming that tastes and earning abilities are perfectly correlated, we prove that everyone must face a marginal price for the public sector’s output which strictly exceeds its marginal cost if correlation is positive. These properties provide an economic rationale for the provision of “support for low‐income consumers” as mandated by the universal service and similar regulatory policies. Finally, we show that with correlated characteristics, implementation can be achieved through two separate functions: a pricing function that depends only on the public sector output and a tax function that depends only on income.
Does Government Decentralization Increase Policy Innovation?
Authors: Strumpf Koleman S.
Published: March 2003

The conventional wisdom is that government decentralization promotes policy innovation because it allows for several simultaneous experiments by local governments. However, this ignores a learning externality: successful policy experiments provide useful information for all governments. Local governments will ignore this externality, but a central government should take it into account. This article uses a social learning model to compare policy innovation under centralization and decentralization. Centralization leads to more policy innovation if the local governments are relatively homogeneous or large in number. However, decentralization may induce more policy innovation if there are multiple experimental policies available.
Conspicuous Consumption and Social Segmentation
Authors: Jaramillo Fernando , Moizeau Fabien
Published: March 2003

This paper develops the idea that conspicuous consumption has an impact on social segmentation, i.e., on the partition of the society into communities. Even though agents do not value conspicuous goods per se, they are competing in a signalling race in order to benefit from social interactions within a community. First, we study the equilibria of this model defining the optimal strategies and the equilibrium partition that characterizes pooling and separating equilibria. In a second step, as conspicuous consumption is a pure waste of money, we study a possible Pareto–improving taxation policy.
Regional Exchange Rate Indexes for the United States
Authors: Clark Don P. , Sawyer W. Charles , Sprinkle Richard L.
Published: March 2003

In this paper we construct exchange rate indexes for the nine U.S. Bureau of the Census regions. The results indicate there are nontrivial differences between them and an identically created overall U.S. exchange rate index. The national index is cointegrated with only two of these regional indexes, and in a Granger sense, it is causing one regional index. In addition, our results indicate that two of the regional exchange rate indexes are interchangeable with the national index. These results show that researchers investigating how exchange rate changes affect regional exports or regional economic growth should be cautious in making inferences based upon a national exchange rate index.
Seeing Through the Fog: Love and Injustice in Bleak House
Authors: McClure Joyce Kloc
Published: March 2003

The author takes up a provocative question poised by Charles Taylor about the relationship between our commitments to a good such as neighbor love and the possibilities of achieving and sustaining social justice. Taylor's concern is not only that we make such a commitment but that we make it in such a way that we avoid its ability to lead us towards injustice rather than justice. After articulating conceptions of love, justice, and injustice, the author turns to Charles Dickens's treatment of love and injustice in Bleak House, to explore more fully how love can lead to injustice, and also its potential role in promoting justice. Dickens's view, profoundly shaped by his own sense of Christian virtues, helps us see the inner workings of love, justice, and injustice, so that we can appreciate their interconnectedness anew and understand better the urgency of Taylor's question for our time.
Hugh of St. Victor and the Authorship of In Threnos Ieremiae*
Authors: Moore Rebecca
Published: March 2003

The great esteem in which Hugh of St. Victor (d. 1141) was held by his contemporaries and by subsequent theologians led to the false attribution of a number of works to the Victorine. The prophetic commentaries have been especially challenged, while In Threnos Ieremiae alone has remained unquestioned. This article questions the authenticity of that work, however, because it departs in both content and style from Hugh’s authentic commentaries. A computer search on words and phrases using the Patrologia Latina Database turned up a number of polemical comments about Jews much at odds with Hugh’s generally irenic attitude toward Jews. Moreover, the search revealed items unique to the Lamentations commentary, but not unique to the non‐authentic works and the disputed prophetic commentaries. Although the literal explanations in Lamentations do generally resemble Hugh’s style, the additions of allegorical and moral explanations are unusual. They may indicate that a second party added to an initial work by Hugh. The polemical use of the words perdy, blindness, Jew, and Judaism, however, suggests authorship by another, particularly since these expressions turn up in other works no longer credited to Hugh of St.Victor.
The Nonjurors and the Counter Enlightenment: Some Illustration
Authors: Leighton C. D. A.
Published: March 2003

The article argues, ﬁrstly, that in view of the relationship between Protestantism and the English Enlightenment it is in distinctively non‐Protestant religious thought, within or without the Church of England, that the central themes of the English Counter Enlightenment are to be sought. The writings of the Nonjurors can and should therefore be seen as possessing a wider signiﬁcance than that derived from the history of theology. They constitute an important part of the Enlightenment/Counter Enlightenment debates, and this ﬂows naturally from the position they occupy in relation to the Catholic and Reformation traditions. The study exempliﬁes this view with reference to the writers of the Usager movement. There is, in the second part, a statement of the fundamental theological causes of the Usager schism. The third part displays the signiﬁcance of these concerns to the Enlightenment/Counter Enlightenment debates and in particular to the central matter of these debates — the epistemological and institutional location of authority.
Marxism and Anticlericalism: The Parti Ouvrier Français and the War against Religion, 1882–1905
Authors: Stuart Robert
Published: March 2003

This article analyses the relationship between French anticlericalism — one of the strongest forces within that nation’s political culture — and the Parti Ouvrier Français — the embodiment of nascent Marxism in France. It reveals the ambiguities of the POF’s engagement with religion, which ranged from a violent hostility towards the anticlericals, seen as diverting workers from their struggle against capital, to the development of a ferocious socialist critique of the church, seen as an instrument of capitalist oppression. The Marxists’ critique of anticlericalism is awarded particular attention, given the usual association between the French Left and hostility towards a supposedly reactionary church, and it is suggested that the POF developed an “agnostic” strategy that might well have guided its politics safely through the storms of French religious politics. Instead, the Parti Ouvrier all too frequently echoed the standard leftist rhetoric of priest‐baiting, and even developed its own socialist variant of anticlericalism. The analysis concludes that the resultant aporias in the Parti Ouvrier’s political discourse determined the relative failure of French Marxism’s intervention in the long war between clericals and anti‐clericals.
“Testimonies from the Field”: The Coming of Christian Science to Australia, c. 1890–1910*
Authors: Roe Jill
Published: March 2003

The account of the coming of Christian Science to Australia given in this article is based on testimony contributed by early adherents to the two main church publications, The Christian Science Journal and the Christian Science Sentinel, supplemented by Church records and other sources. The ﬁrst two decades are covered, from the earliest known intimations of interest to the death of Mary Baker Eddy in 1910, when a Christian Science presence in Australia was assured. Interest shown by writer Miles Franklin, and her association with Melbourne adherents such as leading feminist Vida Goldstein, provides the starting point. The focus is on positive responses. It is postulated that in addition to the documentary and expressive value of the testimonies, they point to problems of class and health in turn‐of‐the‐century Australia. A preponderance of women in both the testimonies and the practice is evidenced, and the openness of progressive women to new approaches is noted. With reference to male testimony, it is suggested that further research into responses to American ways in religion by the urban midle class would be very valuable.
“Child of the Clan” or “Child of the Priests”: Life Stories of Two Fipa Catholic Sisters
Authors: Smythe Kathleen R.
Published: March 2003

This paper analyses some of the consequences of Christian conversion and the process of assimilating Catholicism in an area of southwestern Tanzania known as Uﬁpa during the middle of the twentieth century. It is based on several conversations with two Fipa Catholic Sisters, Edwina and Ocilia. Their reﬂections highlight the way in which the Fipa people understood conversion. The period covered is not that of initial mission contact but after substantial conversion to Catholicism had taken place. The paper considers the way in which the conversion process was utilized by different families or lineages or, as Sister Edwina states, one “clan” and another. In the life stories of Edwina and Ocilia, control over their biological and social fertility lies at the heart of the conﬂict over their futures. In effect, the sisters struggled to determine their own place as “child of the clan,” or “child of the priests.”
The case for orthographic knowledge
Authors: Johnston Rhona
Published: March 2003

Scholes (1998) argues that phonemic awareness cannot be the driving force behind reading development, because this skill develops as a consequence of learning to read. Evidence is reviewed which supports the view that the role of phonemic awareness has been overstated, but it is clear that awareness of phonemes in spoken words does make some contribution to the development of word recognition skills. Scholes also argues that due to the irregularities of the English spelling system, a phonics approach to reading cannot work since it relies on knowing what the word is. This ignores the fact that there is a considerable amount of evidence that a phonics‐based approach is a very effective way of teaching reading. Phonics is not a branch of phonetics – children can even ‘sound out’ irregular words and still obtain the correct pronunciation. They may activate words which look and sound like the target word – i.e. activate orthographic information – and select the most appropriate word using contextual information. Although, as Scholes argues, the ultimate purpose of reading is comprehension, the unskilled reader has to learn to recognise the building blocks of the sentence, i.e. words, and failure to capitalise on the alphabetic nature of English would make it as hard to learn to read as Chinese.
Rhymes and phonemes in the common unit task: replications and implications for beginning reading
Authors: Seymour Philip H. K. , Duncan Lynne G. , Bolik Fiona M.
Published: March 2003

Theorists and practitioners in the field of reading development are currently debating the importance of rhymes and phonemes in beginning reading. In a recent study, Duncan, Seymour and Hill (1997) provided evidence that explicit or meta‐ awareness of sound is closely linked to reading strategy. Meta‐awareness was measured by asking beginning readers to identify the ‘common unit’ shared by two spoken words. Results showed that meta‐awareness of phonemes emerged prior to meta‐awareness of rhyme, and that reading strategy followed a similar small‐to‐large progression. This study reports on a replication of the ‘common unit’ task which includes modifications to the original procedure (randomisation of conditions, increased practice, removal of positional references from instructions). The results confirm the pattern observed in the original study. Beginning readers learning by a mixed method can identify shared phonemes but not shared rimes in the common unit task. The implications of this and similar replications are discussed.
Progress and performance in National Literacy Strategy classrooms
Authors: Fisher Ros , Lewis Maureen , Davis Bernie
Published: March 2003

This paper presents evidence from an ESRC funded research study into the implementation of the Literacy Hour in small rural schools in England. It supports evidence from national UK data that progress in literacy was made during the first year in which the Literacy Hour was operative. However, evidence from this small‐scale study shows progress being different in each class. Evidence is also presented to show that reading scores provide only a partial picture and that progress in writing may be evident in different classes. It is argued that following the Literacy Hour is not enough but that how teachers teach and the tasks they set during this classroom time have implications for the kind of progress made.
High school students’ literacy practices and identities, and the figured world of school
Authors: Luttrell Wendy , Parker Caroline
Published: March 2003

Conventional wisdom holds that American teenagers do not read or write – that they are a media‐driven group who prefer movies, television and playing video games. Ethnographic data gathered in the High School Literacy Project, a study of four North Carolina high schools, showed a far different picture of teenage literacy. This paper reports on partial findings of the larger study and argues that students use their literacy practices to form their identities within, and sometimes in opposition to, the figured worlds of school, work and family. Many students look to school to provide formal literacy experiences, but find their reading and writing passions at odds with the demands of the school curriculum.
Mutual compensation between L1 reading ability and L2 language proficiency in L2 reading comprehension
Authors: Yamashita Junko
Published: March 2003

The present study investigates the contribution of first language (L1) reading ability and second or foreign language (L2) proficiency to L2 reading comprehension, by focusing on the compensation between L1 reading ability and L2 proficiency. Two research questions were addressed: (1) does high L1 reading ability compensate for low L2 language proficiency? (2) does high L2 language proficiency compensate for low L1 reading ability? Participants were 241 Japanese university students learning English as a foreign language. They were divided into three levels (high, middle, low) according to the levels of their L1 reading ability and L2 language proficiency. Effects of these two factors on L2 reading ability were analysed by analysis of variance. A multiple regression analysis to estimate a compensation model was also applied. Results provided positive answers to both research questions. The present study thus demonstrates the mutual compensation between L1 reading ability and L2 proficiency, which works in order to achieve the highest possible level of L2 reading comprehension for readers with different ability backgrounds in L1 reading and L2 proficiency.
Phonological deficit and the reliance on orthographic approximation for reading: a follow‐up study on an English‐Japanese bilingual with monolingual dyslexia
Authors: Wydell Taeko N. , Kondo Tadahisa
Published: March 2003

A follow‐up study was conducted on AS, previously reported as an English‐Japanese bilingual with monolingual phonological dyslexia in English (Wydell and Butterworth, 1999). It was hypothesised that AS's fundamental deficit which lead to his dyslexia in English would still persist despite him successfully taking a BSc course in an English‐speaking country. AS and his Japanese and English control participants were asked to read aloud a target stimulus first, and then to decide whether the target was a word or nonword. Unlike the control participants, AS showed a marked dissociation between his performance in the lexical (orthographic and phonological) decision and the word naming tasks. Often those words and pseudo‐homophones (e.g. neym), which AS read erroneously, were correct in the decision tasks – the target pseudo‐homophone or word was substituted by another orthographically similar word. The results thus demonstrated that his reading of unfamiliar words or nonwords is essentially based on orthographic approximation using the visual similarities between words. The results confirmed the earlier finding that AS has a core phonological deficit which led to his dyslexia but never affected his reading in Japanese. The results also confirmed that this deficit persists when reading in English. This implies that whatever the neurological abnormality that AS may have, this only affects certain languages, and this abnormality persists with time.
Statistical Evidence in Discrimination Cases
Authors: Gastwirth Joseph L.
Published: March 2003

Statistical data and analyses are used as circumstantial evidence indicating that race, gender, age or another legally prohibited factor was a significant cause of an unfavourable employment or governmental decision. This paper discusses the role of statistical evidence in the context of the legal process. Changepoint techniques to determine when an employment practice changed and Cornfield’s approach to examining alleged flaws in a statistical analysis to ensure that they are sufficiently severe to affect the final inference are illustrated. The importance of understanding the underlying process before deciding on the appropriate statistical methodology is described in the context of a promotion case where the routine use of Fisher’s exact test, without checking that the original hirings were fair, can lead to anomalous results.
The Relative Impact of Interviewer Effects and Sample Design Effects on Survey Precision
Authors: O’Muircheartaigh Colm , Campanelli Pamela
Published: March 2003

One of the principal sources of error in data collected from structured face-to-face interviews is the interviewer. The other major component of imprecision in survey estimates is sampling variance. It is rare, however, to find studies in which the complex sampling variance and the complex interviewer variance are both computed. This paper compares the relative impact of interviewer effects and sample design effects on survey precision by making use of an interpenetrated primary sampling unit–interviewer experiment which was designed by the authors for implementation in the second wave of the British Household Panel Study as part of its scientific programme. It also illustrates the use of a multilevel (hierarchical) approach in which the interviewer and sample design effects are estimated simultaneously while being incorporated in a substantive model of interest.
Cofactors and Markers of Disease Progression in Human Immunodeficiency Virus Infection
Authors: Sabin C. A. , Mocroft A. , Cozzi Lepri A. , Phillips A. N.
Published: March 2003

The identification of factors which are related to human immunodeficiency virus (HIV) disease progression, either by a direct interaction with HIV to increase the rate of disease progression or by providing an indication of an infected individual’s likely prognosis, can have great value when understanding HIV pathogenesis and in the development of novel therapeutic approaches. This paper describes the roles of the CD4 cell count and the viral load as markers of disease progression and discusses the recent findings on chemokine receptors in HIV infection. Our current knowledge on these factors is summarized and unresolved statistical issues are highlighted.
Modelling Consumers’ Use of Products
Authors: Romaniuk H. , Skinner C. J. , Cooper P. J.
Published: March 2003

Patterns of consumers’ use of products are of interest to manufacturers. This paper is concerned with modelling diary data on the use of one product, shampoo, recorded to the nearest hour by over 500 men during 1 week. A binary response multilevel model is developed, building on similar models for consumer purchase data. The model allows for a dependence on the number of days since last use. The results of fitting various versions of this model are discussed. A problem is that the number of days since last use is missing for all times up to the first use. An approximate EM approach is considered to deal with this problem.
Estimation in Large Cross Random-Effect Models by Data Augmentation
Authors: Clayton David , Rasbash J.
Published: March 2003

Estimation in mixed linear models is, in general, computationally demanding, since applied problems may involve extensive data sets and large numbers of random effects. Existing computer algorithms are slow and/or require large amounts of memory. These problems are compounded in generalized linear mixed models for categorical data, since even approximate methods involve fitting of a linear mixed model within steps of an iteratively reweighted least squares algorithm. Only in models in which the random effects are hierarchically nested can the computations for fitting these models to large data sets be carried out rapidly. We describe a data augmentation approach to these computational difficulties in which we repeatedly fit an overlapping series of submodels, incorporating the missing terms in each submodel as ‘offsets’. The submodels are chosen so that they have a nested random-effect structure, thus allowing maximum exploitation of the computational efficiency which is available in this case. Examples of the use of the algorithm for both metric and discrete responses are discussed, all calculations being carried out using macros within the MLwiN program.
Selecting Treatments: A Decision Theoretic Approach
Authors: Claxton Karl , Lacey Larry F. , Walker Stephen G.
Published: March 2003

The paper looks at the problem of comparing two treatments, for a particular population of patients, where one is the current standard treatment and the other a possible alternative under investigation. With limited (finite) financial resources the decision whether to replace one by the other will not be based on health benefits alone. This motivates an economic evaluation of the two competing treatments where the cost of any gain in health benefit is scrutinized; it is whether this cost is acceptable to the relevant authorities which decides whether the new treatment can become the standard. We adopt a Bayesian decision theoretic framework in which a utility function is introduced describing the consequences of making a particular decision when the true state of nature is expressed via an unknown parameter θ (this parameter denotes cost, effectiveness, etc.). The treatment providing the maximum posterior expected utility summarizes the decision rule, expectations taken over the posterior distribution of the parameter θ.
An Ecological Investigation of the Incidence of Cancer in Welsh Children for the Period 1985–1994 in Relation to Residence near the Coastline
Authors: Steward John , John Gareth
Published: March 2003

An alarming report from an environmental pressure group raised concerns about childhood leukaemia and the Irish Sea. In response, this ecological study explores the hypotheses that childhood cancer rates are increased by living near the coast of Wales, especially in the north, and in particular near estuaries and mud-flats. Using Poisson regression to adjust for possible confounding variables, no evidence was found for a coastline proximity effect at the level of census wards (5 km). Moreover the rates were significantly lower near estuaries than for the rest of the coast, but there was a small but non-significant increase near mud-flats. Case–control modelling of postcoded cases living within the coastal wards using Stone’s method also failed to detect any monotonic reduction in relative risk near the coastline.
Methods for Eliciting Aetiological Clues from Geographically Clustered Cases of Disease, with Application to Leukaemia–Lymphoma Data
Authors: Williams Joan R. , Alexander Freda E. , Cartwright Ray A. , McNally Richard J. Q.
Published: March 2003

The nearest neighbour analysis method has been developed to determine whether a disease case may be regarded as being unusually close to other neighbouring cases of the same disease. Using this method, each disease case is classified as spatially ‘clustered’ or ‘non-clustered’. The method is also used to provide a test for global clustering. ‘Clusters’ are constructed by amalgamating geographically neighbouring clustered cases into one contiguous ‘cluster area’. This paper describes a method for studying differences between clustered and non-clustered cases, in terms of case ‘attributes’. These attributes may be person related, such as age and sex, or area based, such as geographical isolation. The area-based variables are subject to geographical correlation. The comparison of clustered and non-clustered cases may reveal similarities or differences, which may, in turn, give clues to disease aetiology. A method for studying ‘linkage’ or similarities in attributes between cases that occur in the same clusters is also described. The methods are illustrated by application to incidence data for leukaemias and lymphomas.
A Shared Component Model for Detecting Joint and Selective Clustering of Two Diseases
Authors: Knorr-Held Leonhard , Best Nicola G.
Published: March 2003

The study of spatial variations in disease rates is a common epidemiological approach used to describe the geographical clustering of diseases and to generate hypotheses about the possible ‘causes’ which could explain apparent differences in risk. Recent statistical and computational developments have led to the use of realistically complex models to account for overdispersion and spatial correlation. However, these developments have focused almost exclusively on spatial modelling of a single disease. Many diseases share common risk factors (smoking being an obvious example) and, if similar patterns of geographical variation of related diseases can be identified, this may provide more convincing evidence of real clustering in the underlying risk surface. We propose a shared component model for the joint spatial analysis of two diseases. The key idea is to separate the underlying risk surface for each disease into a shared and a disease-specific component. The various components of this formulation are modelled simultaneously by using spatial cluster models implemented via reversible jump Markov chain Monte Carlo methods. We illustrate the methodology through an analysis of oral and oesophageal cancer mortality in the 544 districts of Germany, 1986–1990.
A Two-Phase Sampling Scheme with Applications to Auditing or Sed Quis Custodiet Ipsos Custodes?
Authors: Barnett V. , Haworth J. , Smith T. M. F.
Published: March 2003

External auditors such as the National Audit Office (NAO) are the final arbiters on the level of error in accounts presented to them by their clients, and the accuracy or otherwise of individual transactions. In coming to a view on the level of error, they are expected to carry out the audit effectively and efficiently, and therefore need to make the best possible use of all the information at their disposal, even when some of the information may not be totally accurate. We consider the particular situation where the NAO is given access to the results of tests on a relatively large random sample of transactions, typically conducted by the client’s internal auditors. A two-phase sampling scheme arises when the NAO subsequently assesses the quality of the client’s data by retesting a subsample of these transactions. The paper discusses methodologies for combining the two sets of data to produce optimum estimates of the proportion of transactions in error (the error rate) and of the level of monetary error in the account. Although a maximum likelihood approach yields a relatively straightforward solution to the error rate problem, there is no uniformly optimum way to estimate the monetary error. Three possible methods are proposed, and the results of a series of simulation experiments to compare their performance under a variety of audit conditions is described.
Some Practical Issues in the Evaluation of Heterogeneous Labour Market Programmes by Matching Methods
Authors: Lechner Michael
Published: March 2003

Recently several studies have analysed active labour market policies by using a recently proposed matching estimator for multiple programmes. Since there is only very limited practical experience with this estimator, this paper checks its sensitivity with respect to issues that are of practical importance in this kind of evaluation study. The estimator turns out to be fairly robust to several features that concern its implementation. Furthermore, the paper demonstrates that the matching approach per se is no panacea for solving all the problems of evaluation studies, but that its success depends critically on the information that is available in the data. Finally, a comparison with a bootstrap distribution provides some justification for using a simplified approximation of the distribution of the estimator that ignores its sequential nature.
Boundary Aware Estimators of Integrated Density Derivative Products
Authors: Cheng Ming-Yen
Published: March 2003

Integrated squared density derivatives are important to the plug-in type of bandwidth selector for kernel density estimation. Conventional estimators of these quantities are inefficient when there is a non-smooth boundary in the support of the density. We introduce estimators that utilize density derivative estimators obtained from local polynomial fitting. They retain the rates of convergence in mean-squared error that are familiar from non-boundary cases, and the constant coefficients have similar forms. The estimators and the formula for their asymptotically optimal bandwidths, which depend on integrated products of density derivatives, are applied to automatic bandwidth selection for local linear density estimation. Simulation studies show that the constructed bandwidth rule and the Sheather–Jones bandwidth are competitive in non-boundary cases, but the former overcomes boundary problems whereas the latter does not.
Acceleration of the EM Algorithm by using Quasi-Newton Methods
Authors: Jamshidian Mortaza , Jennrich Robert I.
Published: March 2003

The EM algorithm is a popular method for maximum likelihood estimation. Its simplicity in many applications and desirable convergence properties make it very attractive. Its sometimes slow convergence, however, has prompted researchers to propose methods to accelerate it. We review these methods, classifying them into three groups: pure, hybrid and EM-type accelerators. We propose a new pure and a new hybrid accelerator both based on quasi-Newton methods and numerically compare these and two other quasi-Newton accelerators. For this we use examples in each of three areas: Poisson mixtures, the estimation of covariance from incomplete data and multivariate normal mixtures. In these comparisons, the new hybrid accelerator was fastest on most of the examples and often dramatically so. In some cases it accelerated the EM algorithm by factors of over 100. The new pure accelerator is very simple to implement and competed well with the other accelerators. It accelerated the EM algorithm in some cases by factors of over 50. To obtain standard errors, we propose to approximate the inverse of the observed information matrix by using auxiliary output from the new hybrid accelerator. A numerical evaluation of these approximations indicates that they may be useful at least for exploratory purposes.
Fast EM-type Implementations for Mixed Effects Models
Authors: Meng Xiao-Li , Van Dyk D.
Published: March 2003

The mixed effects model, in its various forms, is a common model in applied statistics. A useful strategy for fitting this model implements EM-type algorithms by treating the random effects as missing data. Such implementations, however, can be painfully slow when the variances of the random effects are small relative to the residual variance. In this paper, we apply the ‘working parameter’ approach to derive alternative EM-type implementations for fitting mixed effects models, which we show empirically can be hundreds of times faster than the common EM-type implementations. In our limited simulations, they also compare well with the routines in S-PLUS® and Stata® in terms of both speed and reliability. The central idea of the working parameter approach is to search for efficient data augmentation schemes for implementing the EM algorithm by minimizing the augmented information over the working parameter, and in the mixed effects setting this leads to a transfer of the mixed effects variances into the regression slope parameters. We also describe a variation for computing the restricted maximum likelihood estimate and an adaptive algorithm that takes advantage of both the standard and the alternative EM-type implementations.
Density and Hazard Rate Estimation for Right-Censored Data by Using Wavelet Methods
Authors: Antoniadis Anestis , Grégoire Gérard , Nason Guy
Published: March 2003

This paper describes a wavelet method for the estimation of density and hazard rate functions from randomly right-censored data. We adopt a nonparametric approach in assuming that the density and hazard rate have no specific parametric form. The method is based on dividing the time axis into a dyadic number of intervals and then counting the number of events within each interval. The number of events and the survival function of the observations are then separately smoothed over time via linear wavelet smoothers, and then the hazard rate function estimators are obtained by taking the ratio. We prove that the estimators have pointwise and global mean-square consistency, obtain the best possible asymptotic mean integrated squared error convergence rate and are also asymptotically normally distributed. We also describe simulation experiments that show that these estimators are reasonably reliable in practice. The method is illustrated with two real examples. The first uses survival time data for patients with liver metastases from a colorectal primary tumour without other distant metastases. The second is concerned with times of unemployment for women and the wavelet estimate, through its flexibility, provides a new and interesting interpretation.
Gibbs Sampling for Bayesian Non-Conjugate and Hierarchical Models by Using Auxiliary Variables
Authors: Damlen P. , Wakefield J. , Walker S.
Published: March 2003

We demonstrate the use of auxiliary (or latent) variables for sampling non-standard densities which arise in the context of the Bayesian analysis of non-conjugate and hierarchical models by using a Gibbs sampler. Their strategic use can result in a Gibbs sampler having easily sampled full conditionals. We propose such a procedure to simplify or speed up the Markov chain Monte Carlo algorithm. The strength of this approach lies in its generality and its ease of implementation. The aim of the paper, therefore, is to provide an alternative sampling algorithm to rejection-based methods and other sampling approaches such as the Metropolis–Hastings algorithm.
Extremal Analysis of Processes Sampled at Different Frequencies
Authors: Robinson Michael E. , Tawn Jonathan A.
Published: March 2003

The observed extremes of a discrete time process depend on the process itself and the sampling frequency. We develop theoretical results which show how to account for the effect of sampling frequency on extreme values, thus enabling us to analyse systematically extremal data from series with different sampling rates. We present statistical methodology based on these results which we illustrate though simulations and by applications to sea-waves and rainfall data.
Bayesian Poisson Models for the Graphical Combination of Dependent Expert Information
Authors: Smith Jim Q. , Faria, Jr Álvaro E.
Published: March 2003

A supra-Bayesian (SB) wants to combine the information from a group of k experts to produce her distribution of a probability θ. Each expert gives his counts of what he thinks are the numbers of successes and failures in a sequence of independent trials, each with probability θ of success. These counts, used as a surrogate for each expert's own individual probability assessment (together with his associated level of confidence in his estimate), allow the SB to build various plausible conjugate models. Such models reflect her beliefs about the reliability of different experts and take account of different possible patterns of overlap of information between them. Corresponding combination rules are then obtained and compared with other more established rules and their properties examined.
Testing Generalized Linear and Semiparametric Models Against Smooth Alternatives
Authors: Kauermann Göran , Tutz Gerhard
Published: March 2003

We propose goodness-of-fit tests for testing generalized linear models and semiparametric regression models against smooth alternatives. The focus is on models having both continous and factorial covariates. As a smooth extension of a parametric or semiparametric model we use generalized varying-coefficient models as proposed by Hastie and Tibshirani. A likelihood ratio statistic is used for testing. Asymptotic expansions allow us to write the estimates as linear smoothers which in turn guarantees simple and fast bootstrapping of the test statistic. The test is shown to have √n-power, but in contrast with parametric tests it is powerful against smooth alternatives in general.
Generalized Least Squares with Misspecified Serial Correlation Structures
Authors: Koreisha Sergio G. , Fang Yue
Published: March 2003

Summary. The regression literature contains hundreds of studies on serially correlated disturbances. Most of these studies assume that the structure of the error covariance matrix Ω is known or can be estimated consistently from data. Surprisingly, few studies investigate the properties of estimated generalized least squares (GLS) procedures when the structure of Ω is incorrectly identified and the parameters are inefficiently estimated. We compare the finite sample efficiencies of ordinary least squares (OLS), GLS and incorrect GLS (IGLS) estimators. We also prove new theorems establishing theoretical efficiency bounds for IGLS relative to GLS and OLS. Results from an exhaustive simulation study are used to evaluate the finite sample performance and to demonstrate the robustness of IGLS estimates vis-à-vis OLS and GLS estimates constructed for models with known and estimated (but correctly identified) Ω. Some of our conclusions for finite samples differ from established asymptotic results.
Cox Regression in Cohort Studies with Validation Sampling
Authors: Chen Yi-Hau
Published: March 2003

An estimation procedure is proposed for the Cox model in cohort studies with validation sampling, where crude covariate information is observed for the full cohort and true covariate information is collected on a validation set sampled randomly from the full cohort. The method proposed makes use of the partial information from data that are available on the entire cohort by fitting a working Cox model relating crude covariates to the failure time. The resulting estimator is consistent regardless of the specification of the working model and is asymptotically more efficient than the validation-set-only estimator. Approximate asymptotic relative efficiencies with respect to some alternative methods are derived under a simple scenario and further studied numerically. The finite sample performance is investigated and compared with alternative methods via simulation studies. A similar procedure also works for the case where the validation set is a stratified random sample from the cohort.
Familywise Robustness Criteria for Multiple-Comparison Procedures
Authors: Holland Burt , Cheung Siu Hung
Published: March 2003

A criticism of multiple-comparison procedures is that the family of inferences over which an error rate is controlled is often arbitrarily selected, yet the conclusion may depend heavily on the choice of the family. Such ambiguity is most likely in large exploratory studies requiring numerous simultaneous inferences. In ambiguous situations it is desirable that results of multiple-comparison procedures depend little on the chosen family. To assess this, we propose several familywise robustness criteria to evaluate such procedures, and we find some of their properties theoretically and by simulation. Procedures that control the false discovery rate seem to be familywise robust.
Robust Estimation in Generalized Linear Mixed Models
Authors: Yau Kelvin K. W. , Kuk Anthony Y. C.
Published: March 2003

Generalized linear mixed models (GLMMs) are widely used to analyse non-normal response data with extra-variation, but non-robust estimators are still routinely used. We propose robust methods for maximum quasi-likelihood and residual maximum quasi-likelihood estimation to limit the influence of outlying observations in GLMMs. The estimation procedure parallels the development of robust estimation methods in linear mixed models, but with adjustments in the dependent variable and the variance component. The methods proposed are applied to three data sets and a comparison is made with the nonparametric maximum likelihood approach. When applied to a set of epileptic seizure data, the methods proposed have the desired effect of limiting the influence of outlying observations on the parameter estimates. Simulation shows that one of the residual maximum quasi-likelihood proposals has a smaller bias than those of the other estimation methods. We further discuss the equivalence of two GLMM formulations when the response variable follows an exponential family. Their extensions to robust GLMMs and their comparative advantages in modelling are described. Some possible modifications of the robust GLMM estimation methods are given to provide further flexibility for applying the method.