Book review

How to Conduct Self‐administered and Mail Surveys, L. B. Bourque and E. P. Fielder, London, Sage Publications, 1995, 223 pp, £17.50     

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.     

化工原理实验教学软件的开发

介绍了化工原理实验教学软件的基本框架、功能及其用途,软件采用Microsoft Visual Basic 6.0编写,界面友好,功能齐全、操作简单、并可根据实际需要进行功能扩充,为化工原理实验CAI教学与实际应用提供了方便。     

Evaluating correlated outcomes and sources of new information

This paper considers the difficulties associated with evaluating the expected value of additional information when the outcomes of various decision alternatives may be correlated. Such correlation is explained in terms of dependence of outcomes on common exogenous factors and it is argued that decisions regarding what, if any, additional information to collect should take such dependencies into account. A model-based ‘fixed-parameter’ approach to evaluating EVPI in such a context is developed and compared to the traditional ‘fixed-correlation’ approach. The results suggest that different assumptions about the issue of correlation can produce different, sometimes contradictory, conclusions about the expected value of additional information and bence, should be explicitly stated as part of any pre-posterior analysis. A hybrid model encompassing both approaches and rooted in the theory of psychology of inference is then proposed and illustrated.     

Children's Presence in the Neighbourhood: A Social‐Pedagogical Perspective

In this article we discuss some theoretical and methodological perspectives for studying children's neighbourhoods as a social‐pedagogical context. This social‐pedagogical perspective includes a focus in research on a reflective approach based on the acquisition of empirical indicators about the impact of the neighbourhood on children's socialisation. A research outline based on the idea of mapping children's neighbourhoods within their social and historical context is presented as one possible example of such an analysis.     

Communicating Risks and Benefits from Fish Consumption: Impact on Belgian Consumers' Perception and Intention to Eat Fish

Communicating about the health effects of fish and seafood may potentially result in a conflict situation: increasing intake is desirable because of health and nutritional benefits, but higher consumption may also lead to an increased intake of potentially harmful environmental contaminants. In order to anticipate the communication challenge this conflict may pose, the research presented here aimed to assess the impact of risk/benefit communication on Belgian consumers' fish consumption behavior and fish attribute perception. Data were collected in June 2005 from a sample of 381 women, aged between 20 and 50 years. An experimental design consisting of four message conditions (benefit‐only; risk‐only; benefit‐risk; and risk‐benefit) combined with three information sources (fish and food industry; consumer organization; government) was used. Exposure to the benefit‐only message resulted in an increase from a self‐reported fish consumption frequency of 4.2 times per month to an intended fish consumption frequency of 5.1 times per month (+21%), while fish attribute perceptions only marginally improved. The risk‐only message resulted in a strong negative perceptual change in the range of two points on a seven‐point scale. This translated into an 8% decrease of behavioral intention (from eating fish 4.5 times per month to an intention of eating fish 4.1 times per month). Balanced messages referring to both risks and benefits yielded no significant change in behavioral intention, despite a significant worsening of fish attribute perception. The presentation order of benefits and risks in the balanced message showed a tendency to affect both behavioral intention and attribute perception, with the first message component being most influential. Information source did not yield any significant impact either on behavioral intention or on attribute perceptions, independent of the message content. The results from this study provide valuable insights for future risk/benefit and balanced communication about seafood.     

Semiparametric Bayesian classification with longitudinal markers

Summary.  We analyse data from a study involving 173 pregnant women. The data are observed values of the β human chorionic gonadotropin hormone measured during the first 80 days of gestational age, including from one up to six longitudinal responses for each woman. The main objective in this study is to predict normal versus abnormal pregnancy outcomes from data that are available at the early stages of pregnancy. We achieve the desired classification with a semiparametric hierarchical model. Specifically, we consider a Dirichlet process mixture prior for the distribution of the random effects in each group. The unknown random-effects distributions are allowed to vary across groups but are made dependent by using a design vector to select different features of a single underlying random probability measure. The resulting model is an extension of the dependent Dirichlet process model, with an additional probability model for group classification. The model is shown to perform better than an alternative model which is based on independent Dirichlet processes for the groups. Relevant posterior distributions are summarized by using Markov chain Monte Carlo methods.     

西方会计信息价值相关性研究的简要回顾

从上世纪30年代以来,会计信息价值相关性一直是西方学术界致力研究的重大课题.国外的研究表明,要发展和完善资本市场,必须充分发挥会计信息的作用,同时也必须加强会计信息价值相关性水平的经验研究.近几年,尽管已有专家、学者对我国资本市场会计信息质量进行了研究,但总体上讲,尚缺乏系统性、全面性.另外,在引荐和借鉴西方比较成熟的证券市场理论和研究方法方面也存在着一定的"滞后"现象.这将不利于我国资本市场的长期发展和会计信息质量的提高.因此,本文按西方会计信息价值相关性的经验研究成果为主线索,对其理论发展进行系统性回顾,希望这些研究成果对我国会计信息价值相关性研究的发展有所帮助.同时,就促进我国会计信息价值相关性研究提出了一些政策建议.     

Remarriage,Unmarried Cohabitation,Living Apart Together: Partner Relationships Following Bereavement or Divorce

Substantial proportions of people enter into new partner relationships after bereavement or divorce. Nowadays in Europe, unmarried cohabitation and living‐apart‐together relationships are frequently opted for at repartnering. Drawing on the Netherlands’ Living Arrangements and Social Networks survey of men and women aged 55 to 89 years (N = 4,494), this article explicates the determinants that lead widowed or divorced people to enter into old and new types of partner relationships. Cox proportional hazard regression analyses revealed that age at most recent union dissolution, the number of partner dissolutions, working during and after the most recent union dissolution, and other demographic variables are important in weighing the pros and cons of different types of living arrangements.     

An individual treatment programme for sexually abused adult males: description and preliminary findings

Growing recognition of male sexual abuse and its potentially debilitating effects has underscored the need to develop effective treatment interventions for this population. The present study describes an individual treatment programme that was developed for adult males who have experienced childhood sexual abuse. The treatment programme focused on three areas related to sexual abuse, specifically feelings of self‐blame, anger and anxiety. The study also presents preliminary findings on treatment effects, using self‐report measures that five participants completed prior to treatment and at various assessments following treatment termination. Overall findings indicated improvements in behavioural self‐blame, anger, state anxiety and trait anxiety. Treatment did not appear to have an effect on characterological self‐blame over the long term. The study's findings are limited by the reliance on self‐report data and the absence of a comparison group. As such, our findings should be viewed as an initial contribution to the currently limited empirical data on treatment effects for sexually abused adult males. Copyright © 2005 John Wiley & Sons, Ltd.