Adapting by calibration the sample size of a phase III trial on the basis of phase II data

The problem of estimating the sample size for a phase III trial on the basis of existing phase II data is considered, where data from phase II cannot be combined with those of the new phase III trial. Focus is on the test for comparing the means of two independent samples. A launching criterion is adopted in order to evaluate the relevance of phase II results: phase III is run if the effect size estimate is higher than a threshold of clinical importance. The variability in sample size estimation is taken into consideration. Then, the frequentist conservative strategies with a fixed amount of conservativeness and Bayesian strategies are compared. A new conservative strategy is introduced and is based on the calibration of the optimal amount of conservativeness – calibrated optimal strategy (COS). To evaluate the results we compute the Overall Power (OP) of the different strategies, as well as the mean and the MSE of sample size estimators. Bayesian strategies have poor characteristics since they show a very high mean and/or MSE of sample size estimators. COS clearly performs better than the other conservative strategies. Indeed, the OP of COS is, on average, the closest to the desired level; it is also the highest. COS sample size is also the closest to the ideal phase III sample size M_I, showing averages and MSEs lower than those of the other strategies. Costs and experimental times are therefore considerably reduced and standardized. However, if the ideal sample size M_I is to be estimated the phase II sample size n should be around the ideal phase III sample size, i.e. n?2M_I/3. Copyright © 2010 John Wiley & Sons, Ltd.     

THE DUALITY DIAGRAM IN DATA ANALYSIS: EXAMPLES OF MODERN APPLICATIONS

Today's data-heavy research environment requires the integration of different sources of information into structured datasets that can not be analyzed as simple matrices. We introduce an old technique, known in the European data analyses circles as the Duality Diagram Approach, put to new uses through the use of a variety of metrics and ways of combining different diagrams together. This issue of the Annals of Applied Statistics contains contemporary examples of how this approach provides solutions to hard problems in data integration. We present here the genesis of the technique and how it can be seen as a precursor of the modern kernel based approaches.     

Electricity consumption prediction with functional linear regression using spline estimators

A functional linear regression model linking observations of a functional response variable with measurements of an explanatory functional variable is considered. This model serves to analyse a real data set describing electricity consumption in Sardinia. The interest lies in predicting either oncoming weekends’ or oncoming weekdays’ consumption, provided actual weekdays’ consumption is known. A B-spline estimator of the functional parameter is used. Selected computational issues are addressed as well.     

人格特质对授权感知的调节效应研究

一、引言 传统的授权理论认为,授权就是将权利分派给其他人以完成特定活动的过程,也就是说,把决策权从组织的一个层级移交到另一个层级(Astly,1984)[1].现代授权理论则认为,授权的本质在于尽可能释放员工的知识、经验和动力,增加员工自我效能感,消除员工"无权"的感觉(Arad & Drasgow ,1994;Conger & Kanungo,1988;Spreitzer,1996).正如Lee和Koh(2001)指出的,授权实际上有两个完全不同的方面,一方面是主管给下属授权的"行为",另一方面是下属感知这种授权行为的"心理状态",即授权感知.     

What's Playing in the Organizational Theater? Collusive Relationships in Management

This article takes as its point of departureconcepts derived from couple therapy to betterunderstand collusive relationships in organizations. Aswe examine these dysfunctional workplace relationships— these interpersonal gridlocks —four main types of collusive superior subordinateinteraction patterns are identified — thenarcissistic, the controlling, the paranoid, and thesadomasochistic — and the consequences of each such dyad in organizationsare explored. In conclusion, the paper presents a numberof recommendations on how to recognize the presence ofsuch collusive arrangements (taking leadership behavior as a point of departure) and suggestspreventive steps that can be taken.     

The role of litigation in human research accountability

This essay examines and analyzes the recent and dramatic series of personal injury lawsuits instituted against those individuals and institutions that conduct and monitor human research. It discusses the social engineering functions of tort litigation, outlines the legal elements and viability of lawsuits against those who conduct and monitor human research, and evaluates and predicts what role tort litigation will play in fulfilling the goals of accountability in the context of human research and human research regulation. In general, tort law engenders two forms of accountability: retrospective and prospective. Retrospective accountability is backward looking, focusing on harms that have already occurred, their culprits, and the reimbursement of individuals for their injuries. Prospective accountability is forward looking in that it encourages actors and institutions to fulfill responsibilities toward individuals in order that harm does not occur, or at least that the risk of harm is decreased. This article argues that research litigation is not, and will probably never become, an effective means of ensuring retrospective accountability in regard to research injuries and ethical violations. Paradoxically though, the current wave of research litigation may serve an important and even key role in encouraging and ensuring prospective accountability.     

Emerging coherence and relations to communication among executive function tasks in toddlers: Evidence from a Latin American sample

Recent work within early executive function (EF) seems to suggest that toddlers show distinct patterns of development, involving poorly correlated performance across EF tasks and significant improvements over relatively short periods of time. The present study sought to extend these findings by investigating evidence for these patterns in toddlers and the existence of more traditional patterns of EF (e.g., correlations between tasks, links to language) when using the same tasks in a novel Latin American sample. Eighty toddlers (18–24 months) and sixty young preschoolers (30–36) months completed a battery of EF tasks, early social communication, and receptive and expressive language measures. Results indicated that toddlers showed similar distinct patterns of development (i.e., few relations between tasks and links to responding to joint attention), but by early preschool a more cohesive EF and links to language were present. Further, work demonstrated significant age (older children outperformed younger children), gender (girls outperformed boys), and socioeconomic differences (satisfied basic needs outperformed unsatisfied basic needs, but only on the snack delay). This work provides evidence for patterns of emerging EF development within this novel cultural sample (and evidence for group differences) that may be supported by communicative and representational development.     

Regulation issues in the Italian local transport system: aligning transactions and governance structures

This paper refers to the concept of public governance in the light of Transaction Cost Economics (TCE). While TCE is well developed and widely applied in the private sector, only a few studies have adopted such framework to investigate the provision of public services. We aim at pointing out the coherence between peculiar typologies of transactions and a given set of governance structures, within Local Public Transport systems. The core of the analysis is the alignment between characteristics of transactions and governance structures. The empirical section addresses these issues referring to three case studies, pointing out an articulated organizational configuration in terms of actors involved and governance structures adopted. The analysis shows an alignment between the choices underlying the design of the local transport system and the outcomes expected in terms of TCE.     

The recruitment and selection of hospital medical consultants

Abstract

The literature on selection has been dominated in recent decades by the ‘prediction’ paradigm. Such an approach requires a substantial number of positions to be filled in order to compute validity coefficients. There are other approaches, using a different paradigm, when concentrated on adjusting the organization and the employee. Here careful analysis of job demands is essential. This article describes such an analysis, taking the medical consultant as an example. The method can be used in an iterative way. It is useful when one has to work with small numbers of positions.