A computationally simple bivariate survival estimator for efficacy and safety

Both treatment efficacy and safety are typically the primary endpoints in Phase II, and even in some Phase III, clinical trials. Efficacy is frequently measured by time to response, death, or some other milestone event and thus is a continuous, possibly censored, outcome. Safety, however, is frequently measured on a discrete scale; in Eastern Cooperative Oncology Group clinical trial E2290, it was measured as the number of weekly rounds of chemotherapy that were tolerable to colorectal cancer patients. For the joint analysis of efficacy and safety, we propose a non-parametric, computationally simple estimator for the bivariate survival function when one time-to-event is continuous, one is discrete, and both are subject to right-censoring. The bivariate censoring times may depend on each other, but they are assumed to be independent of both event times. We derive a closed-form covariance estimator for the survivor function which allows for inference to be based on any of several possible statistics of interest. In addition, we derive its covariance with respect to calendar time of analysis, allowing for its use in sequential studies.     

Determinants of in-group bias: Is group affiliation mediated by guilt-aversion?

In-group favoritism in social dilemma situations is one of Social Identity Theory’s main findings. We investigate what causes the in-group bias: is it merely due to group affiliation or, alternatively, is guilt-aversion moderating the strength of in-group favoring? We induce group membership in a minimal group setting, observe in-/out-group transfers and elicit corresponding beliefs. According to our experimental data group affiliation affects beliefs and explains a substantial part of the bias. Evidence for guilt-aversion is found only when beliefs are elicited before actions.     

Power and perceptions in participatory monitoring and evaluation

This paper examines the assumptions that commonly underpin the design of participatory monitoring and evaluation (PM&E) within development programmes through the examination of a case study of a large rural development programme in Uganda. This case study reveals a mismatch between programme assumptions and participant perceptions, which stymied the implementation of PM&E. In this case, PM&E was based on the assumptions that programme and participant goals were compatible, participants were willing to volunteer and engage themselves for the greater good of their communities, and information sharing and communication was fairly free and open. However, farmers within the programme felt that the bureaucratic and accountability requirements of the programme were not their concern, and were acutely aware of power differences between farmers and programme officials, and between farmers of varying status. The key lesson to be drawn from this case is the need for a heightened awareness of power dynamics and political factors in the design of PM&E.     

USING CONJOINT ANALYSIS TO PREDICT TRIAL AND REPEAT-PURCHASE PATTERNS OF NEW FREQUENTLY PURCHASED PRODUCTS*

A new approach is proposed to evaluate new-product opportunities. This approach uses the distribution of brand-purchase probability of the new product over a population of potential customers and the outputs from conjoint analysis. The heterogeneous distribution of brand-purchase probability is expressed by a beta binomial brand-choice model compounded with a negative binomial product-class purchase-incidence model. The resulting model provides a way to predict trial and repeat-purchase patterns of new-product concepts. The paper discusses the development of the model. It also discusses issues of measurement, estimation, testing, and implementation of the proposed approach based on actual empirical data.     

Extended scaled prediction variance optimality for modified central composite design

Robust parameter designs (RPDs) enable the experimenter to discover how to modify the design of the product to minimize the effect due to variation from noise sources. The aim of this article is to show how this amount of work can be reduced under modified central composite design (MCCD). We propose a measure of extended scaled prediction variance (ESPV) for evaluation of RPDs on MCCD. Using these measures, we show that we can check the error or bias associated with estimating the model parameters and suggest the values of α recommended for MCCS under minimum ESPV.     

Generalized minimum aberration mixed-level orthogonal arrays: A general approach based on sequential integer quadratically constrained quadratic programming

Orthogonal fractional factorial designs and in particular orthogonal arrays (OAs) are frequently used in many fields of application, including medicine, engineering, and agriculture. In this article, we present a methodology and an algorithm to find an OA, of given size and strength, which satisfies the generalized minimum aberration criterion. The methodology is based on the joint use of polynomial counting functions, complex coding of levels, and algorithms for quadratic optimization and puts no restriction on the number of levels of each factor.     

The contingent futures of the mobile present: automation as possibility

In this article we outline and demonstrate a design anthropological approach to investigating automated mobile futures as a processual opening up of possibilities, rather than as a process of technological innovation. To undertake this we investigate the example of how the car-smartphone relationship is configuring in the contingent circumstances of the mobile present and the implications of this for automated mobile futures. Our discussion is set in the context of the growing possibility that automonous driving (AD) features are increasingly part of everyday mobilities (even if unequally distributed globally) and in which personal mobile smart technologies and artificial intelligence (AI) will exist in some form and will interface with humans and be interoperable with other technologies. In developing this we draw on ethnographic understandings of how people live with the possibilities afforded by technologies in everyday life.     

新生代农民工群体特征研究

自2010年中央一号文件首次提出“新生代农民工”说法,新生代农民工开始成为社会各界关注的对象,通过梳理相关文献大致可勾画出新生代农民工所谓“四高”、“一低”、“一薄弱”的社会印象和群体特征。相对其他群体来说,新生代农民工受教育水平并不高,对于农民身份认同相对减弱,城市社区认同较高。对于新生代农民工群体特征的研究应该区分农民工的人口学特征与社会特征,并充分认识到新生代农民工群体的异质性,对其定义和特征把握要注意从与周围群体和代际关系中共同考虑。     

水利水电工程移民群体性事件类型探讨——基于QW省水电移民社会稳定调查

目前,水利水电工程移民是中国社会中最不稳定的群体之一,不稳定的主要表现之一就是易发生＂群体性事件＂,对区域社会稳定构成直接威胁。政府在管理和处置水利水电工程移民群体性事件过程中,首先得认清事件的性质和机理,从而快速地找到处理问题的应对方案。而不同类型水利水电工程移民群体性事件的机理不同,其处置过程也不同。因此,要做到具体问题具体分析、具体处置,就有必要对水利水电工程移民群体性事件进行分类。为了突出当前水利水电工程移民群体性事件的主要表现形态、主要矛盾、研究和政策以及政府管理应关注的重点,结合对QW省水电移民社会稳定调查,本文按照事件规模、参与主体、性质、影响范围、引致原因等十余种基本标准,对水利水电工程移民群体性事件进行了划分。