Type I error and power in trials with one interim futility analysis

Futility analysis reduces the opportunity to commit Type I error. For a superiority study testing a two‐sided hypothesis, an interim futility analysis can substantially reduce the overall Type I error while keeping the overall power relatively intact. In this paper, we quantify the extent of the reduction for both one‐sided and two‐sided futility analysis. We argue that, because of the reduction, we should be allowed to set the significance level for the final analysis at a level higher than the allowable Type I error rate for the study. We propose a method to find the significance level for the final analysis. We illustrate the proposed methodology and show that a design employing a futility analysis can reduce the sample size, and therefore reduce the exposure of patients to unnecessary risk and lower the cost of a clinical trial. Copyright © 2004 John Wiley & Sons, Ltd.     

A Re-Examination of the Suicide Rates in Taiwan

This paper examines the suicide rates of 23 cities and counties in Taiwan from 1983 to 2001. We found that a combination of economic and social variables can significantly account for the tremendous variations in suicide rates across Taiwan’s cities and counties over the last two decades. The level of income per capita in a region appears as the most important predictor of suicide rates. However, some sociological correlates (such as divorce rate) which were less powerful in explaining suicide rate variations in the earlier study appear to exert more significant influence over suicide rates when eight more recent years of information are added, as in the current study. This study also uncovered several gender differences in the determination of regional suicide rates, such as the proportion of elderly population in the region, and the impacts of earthquake and unemployment. Furthermore, this study confirmed the linkages between natural disaster (earthquake) and suicide, between economic and social miseries (unemployment and divorce, respectively) and suicide, as well as those between demographics (aboriginal and elderly sub-population groups) and suicide. This may help to identify high-risk groups or areas where suicide prevention and intervention efforts should be concentrated on or directed to. Lastly, the local suicide crisis-intervention agencies are found to be significantly effective in reducing suicide rates of the community they serve.      

我国开展远程研究生教育的思考

在我国中心城市开展远程研究生教育符合大众化高等教育和学习化社会的要求,符合我国国情和国际远程教育发展以促进素质教育的深入开展和经济社会的进一步发展的大趋势。因此,我国应借鉴国内外远程教育的成功经验,尽早推出远程研究生教育计划。     

Taiwanese–Canadian Mothers' Beliefs About Personal Freedom for Their Young Children

This study examined Taiwanese–Canadian mothers’ conceptions of personal freedom in everyday situations for their children and the influence of acculturation on their beliefs. Forty mothers of six‐ to eight‐year‐old children participated in a semistructured interview and sorting task. Interview responses revealed that, regardless of acculturation, child decision‐making was important and that mothers should negotiate and compromise with their child on everyday issues such as clothing, food, activities, daily routine and homework. They believed that child resistance was motivated by the children's personal interests, laziness, limit testing and their emotional state. Sources of conflict were resolved by parental authority, discussing/negotiating and conceding to the child. The sorting task also revealed that personal issues were judged as within their children's jurisdiction.     

公司治理的演进论解释

本文沿着探究不同治理模式差异化的原因及其影响机理,窥视不同治理模式的核心问题,分析影响公司治理演进的因素的路径,对公司治理演进何以形成较为引人注目的个性化、多样化、趋同化三种趋势作了理论解释。认为当前学术界的研究视野过度地聚焦于公司治理演进的模式比较、演进趋向预测等表层问题,而暂时忽视了对公司治理演进的理论的探寻,是无益的。并提出路径依赖理论、多重制度均衡理论、合约性质理论可作为解释公司治理演进的理论根据,其各自的解释力如何,有待深入研究。     

水利企业建立现代企业制度研究

水利企业建立现代企业制度并不一定要把所有的企业都改造成股份制企业 ,应根据企业提供产品的性质和企业所处生产领域的不同 ,选择不同类型的企业模式 ,并不断创新。     

Middle‐Class African American Parents’ Conceptions of Parenting in Early Adolescence

Conceptions of parenting were examined in 87 middle‐class African American parents (87 mothers and 51 fathers) of early adolescents (M= 13.11 years of age). Using semistructured interviews, parents were queried about two developmentally salient issues of early adolescence: parental limit‐setting and adolescent independence. Parents primarily defined firm limits in terms of nonnegotiation, strongly endorsed setting firm limits regarding a range of issues, and justified the importance of limits by focusing on adolescents’ socialization and psychological development. Mothers rated limiting adolescents’ behavior as more important than permitting or encouraging adolescents’ independence. Limits were seen as more important by mothers of younger rather than older early adolescent females, but mothers encouraged independence more for younger rather than older early adolescent males. Mothers permitted independent decisions regarding a limited range of issues such as clothes and appearance, based on psychological concerns with adolescents’ developing autonomy and competence; they encouraged independence primarily by encouraging greater responsibility. The results demonstrate that there is considerable heterogeneity in African American parents’ beliefs and goals about parenting in early adolescence.