Choice of alpha spending function and time points in clinical trials with one or two interim analyses

One characterization of group sequential methods uses alpha spending functions to allocate the false positive rate throughout a study. We consider and evaluate several such spending functions as well as the time points of the interim analyses at which they apply. In addition, we evaluate the double triangular test as an alternative procedure that allows for early termination of the trial not only due to efficacy differences between treatments, but also due to lack of such differences. We motivate and illustrate our work by reference to the analysis of survival data from a proposed oncology study. Such group sequential procedures with one or two interim analyses are only slightly less powerful than fixed sample trials, but provide for the strong possibility of early stopping. Therefore, in all situations where they can practically be applied, we recommend their routine use in clinical trials. The double triangular test provides a suitable alternative to the group sequential procedures in that they do not provide for early stopping with acceptance of the null hypothesis. Again, there is only a modest loss in power relative to fixed sample tests. Copyright © 2004 John Wiley & Sons, Ltd.     

Strategic spatial planning on the island of Ireland

The central argument in this article is that recent advances in strategic spatial planning on the island of Ireland have been considerably enhanced through the medium of the European Spatial Development Perspective. This has provided a shared technical vocabulary and an imperative to imagine possibilities which transcend the border between Northern Ireland and the Republic of Ireland to a greater and lesser extent, depending on the sensitivities of the actors concerned. Particular attention is given to the role played by very different participatory processes in helping to shape these spatial agendas. The paper concludes by identifying an action‐oriented commitment to sustainable development as the key strategic choice in advancing the logic of territorial interdependence.     

Peer Led Focus Groups and Young People

Peer led focus groups, a qualitative social science research method, and their use with young people are examined. The paper outlines three developments that have contributed to their emergence, namely: traditional focus groups, peer education and participatory research. Drawing on a study in progress, the advantages and challenges associated with peer led focus groups are discussed. A key benefit is that the power differential between the adult researcher and the researched is removed, at least at the point of data collection, rendering peer led focus groups one of few research contexts in which young people can speak collectively with no adult present.     

Adopted Children's Identity and Information Needs

SUMMARY: It has long been accepted that adopted children need access to information about their origins in order to provide a satisfactory answer to the question ‘who am I?’. Such information is seen as vitally important to the formation of a clear and positive sense of identity in adulthood. This study examines the role that such information plays in the formation of personal identity and analyses accounts from 67 adopters of their children's requests for information about their families of origin. Comparisons are made between adopters whose children maintain contact with their families of origin and those whose children have no contact.     

Attitudes and Values of Scottish Farmers: “Yeoman” and “Entrepreneur” as Factors,Not Distinct Types1

Abstract We investigate the validity of the classification of farmers into two or more distinct types on the basis of attitudes, objectives, and values. Factor analysis of data from a survey of farm pluriactivity in Scotland (N=472) shows that attributes ascribed to “yeoman” and “entrepreneur” types emerge as separate factors rather than as a single bipolar factor. No clustering of the factor scores corresponding to distinct types is found. We also present correlations of the factor scores with attitudes to on- and off-farm pluriactivity and with observables such as age and off-farm employment. The desirability of analyzing survey data by methods which do not make assumptions about typology is discussed.     

The O. J. Simpson Verdict: Predictors of Beliefs about Innocence or Guilt

This study examined ethnicity and psychological predictors of beliefs in guilt and innocence in the O. J. Simpson trial. A mixed-gender, multiethnic sample of 441 college students completed measures examining trial beliefs, trial-related attitudes, ethnic identification, pro- and anti-Black attitudes, and authoritarian personality traits. Results revealed that: (1) mean differences existed among ethnic groups on all variables examined; (2) proximal attitudes mediated relations between psychological characteristics and trial outcome beliefs; and (3) specific relations depended (to some extent) on ethnic group membership. Differences within and between ethnic groups may reflect schematic differences due to differential experiences with societal institutions, identification with (or rejection of) mainstream values, and race relations in American society.     

A general maximum likelihood analysis of measurement error in generalized linear models

This paper describes an EM algorithm for maximum likelihood estimation in generalized linear models (GLMs) with continuous measurement error in the explanatory variables. The algorithm is an adaptation of that for nonparametric maximum likelihood (NPML) estimation in overdispersed GLMs described in Aitkin (Statistics and Computing 6: 251–262, 1996). The measurement error distribution can be of any specified form, though the implementation described assumes normal measurement error. Neither the reliability nor the distribution of the true score of the variables with measurement error has to be known, nor are instrumental variables or replication required.Standard errors can be obtained by omitting individual variables from the model, as in Aitkin (1996).Several examples are given, of normal and Bernoulli response variables.     

Contextual influences on personnel policies and programs: an explanatory model

There has been a general absence of research to explain why personnel policies develop in organizations. This article has two objectives: (a) development of a theoretically relevant scheme for clustering personnel policies for analytic purposes, and (b) presentation of an explanatory model suggesting how contextual influences shape these policies.     

'It's in the blood and you're not going to change it': fish harvesters' narrative accounts of injuries and disability

The purpose of this study was to validate Hanson's Learning Profile Inventory (LPI) and Teaching Style Inventory (TSI) further, and to assess the degree to which self-reported style preferences on these scales corresponded to actual observable learning and teaching style behaviors of students and teachers in differing instructional situations. No significant differences were found between the reported and observed learning and teaching style preferences of students and their instructors. Further, student and teacher classifications on the GEFT test of field independence/dependence corresponded to their classifications on the introversion/extroversion scale of the LPI and TSI further clarifying and validating this component of this scale on these two measures. This study was a formative study with a small sample (N=12) due to the burdens of observational ratings, which needs to be replicated with a confirmatory study.