Sequential Hypothesis Tests for Identifying the Minimum Dose with a Threshold Effect

We propose a procedure to identify a lowest dose having greater effect than a threshold dose under the assumption of monotonicity of dose mean response in dose response test. So, we use statistics based on contrasts among sample means and apply a group sequential procedure to our procedure to identify effectively the dose. If we can identify the dose at an early step in the sequential test, since we can terminate the procedure with a few observations, the procedure is useful from an economical point of view. In a simulation studies, we compare the superiority among these procedures based on three contrasts.     

Re-Defining the Who,When, and Where of Mentoring for Professional Statisticians

Organizations tailor their mentoring strategies to accommodate internal resources and preferences, producing different approaches in academic, government, and corporate environments. Across these settings, three common barriers impede effective mentoring of statisticians: overspecialization, time constraints, and geographic dispersion. The authors share mentoring strategies that have emerged at their organization, Mathematica Policy Research, to overcome these obstacles. Practices include creating a methodology working group to unite researchers with diverse backgrounds, integrating mentoring into existing workflows, and harnessing modern technological infrastructure to facilitate virtual mentoring. Although these strategies emerged within a specific professional context, they suggest opportunities for statisticians to expand the channels through which mentorship can occur.     

“无直接利益冲突”的网络发生机制

近年来,"无直接利益冲突"现象在我国似乎形成一种所谓"涟漪效应",其产生的深层根源在于社会分配的不公平及与之相联系的群体异质不公平感的普遍存在;其次也与利益表达机制的不畅通有关。在其产生的过程中,事件触发与演化的关联性往往是通过驱动机制、认同机制、社会比较与自我展示机制和说服争辩机制交互作用表现出来的。在信息时代,"无直接利益冲突"的这些相关发生机制往往与网络极化效应直接相关,即"无直接利益冲突"极易导致网络极化效应的产生,而网络极化效应也促使了"无直接利益冲突"的扩散。而这种双向互动的过程,正是"无直接利益冲突"网络发生机制的作用过程。由此,应给予充分重视。     

开创风物传说研究的新格局——评陈金文先生新著《壮族风物传说的文化研究》

陈佥文先生长期致力于民间传说研究，其新著《壮族风物传说的文化研究》以文化学为理论视角，系统、深入地研究壮族风物传说，开创了民间风物传说研究的新格局。     

Extending systems thinking in planning and evaluation using group concept mapping and system dynamics to tackle complex problems

Group concept mapping (GCM) has been successfully employed in program planning and evaluation for over 25 years. The broader set of systems thinking methodologies (of which GCM is one), have only recently found their way into the field. We present an overview of systems thinking emerging from a system dynamics (SD) perspective, and illustrate the potential synergy between GCM and SD. As with GCM, participatory processes are frequently employed when building SD models; however, it can be challenging to engage a large and diverse group of stakeholders in the iterative cycles of divergent thinking and consensus building required, while maintaining a broad perspective on the issue being studied. GCM provides a compelling resource for overcoming this challenge, by richly engaging a diverse set of stakeholders in broad exploration, structuring, and prioritization. SD provides an opportunity to extend GCM findings by embedding constructs in a testable hypothesis (SD model) describing how system structure and changes in constructs affect outcomes over time. SD can be used to simulate the hypothesized dynamics inherent in GCM concept maps. We illustrate the potential of the marriage of these methodologies in a case study of BECOMING, a federally-funded program aimed at strengthening the cross-sector system of care for youth with severe emotional disturbances.     

Engaging children and youth in research and evaluation using group concept mapping

Group concept mapping is a systematic methodology that recognizes participants’ expertise in their own experiences. In this approach, participants share their diverse knowledge and interpret the data generated by all group members. This approach uniquely blends quantitative and qualitative techniques to create illustrative, structured conceptualizations. In this article, we describe the steps in group concept mapping and report feedback on this method from 37 children and youth who participated in group concept mapping studies. We recommend group concept mapping as an engaging way to involve children and youth in research and evaluation activities.     

Allocation of resources in asymmetric competitions: How do the weak maintain a chance of winning?

To maintain a chance of occasionally beating a stronger player in a competition waged over several fields, a weaker player should give up on some of the fields and concentrate resources on the remaining ones. But when do weak players actually do this? And which fields do they give up when the fields differ in their likelihood of being assessed? We report an experimental study of resource allocation in which asymmetric pairs of players compete over asymmetric fields. Symmetric players and symmetric fields are used for control. We find that players behave as follows: (1) Average wins are the same in the symmetric and asymmetric fields conditions and correspond to relative player strength. (2) The proportion of fields given up on decreases with a player’s greater relative strength, increases for asymmetric field likelihoods, and increases when competitions are framed in meaningful context; this proportion is related to wins. (3) When field likelihoods are asymmetric, players’ resource allocation is correlated with likelihood. Wins generally increase with that correlation but the relation is different for players of different strength. (4) The proportion of fields given up on and the correlation with likelihood change with experience towards the values corresponding to higher wins.     

Revisiting retesting in the estimation of proportions by group testing

In the estimation of a proportion p by group testing (pooled testing), retesting of units within positive groups has received little attention due to the minimal gain in precision compared to testing additional units. If acquisition of additional units is impractical or too expensive, and testing is not destructive, we show that retesting can be a useful option. We propose the retesting of a random grouping of units from positive groups, and compare it with nested halving procedures suggested by others. We develop an estimator of p for our proposed method, and examine its variance properties. Using simulation we compare retesting methods across a range of group testing situations, and show that for most realistic scenarios, our method is more efficient.     

小组工作介入聋儿社会资本的重构

社会资本在聋儿成长中具有非常重要的作用。重构聋儿社会资本成为社会康复的核心内容。在聋儿听力康复过程中,由于聋儿游戏群体的缺失、家长的认识偏误以及家长社会资本的不足等原因,导致聋儿社会资本不足的问题非常突出。文章从小组工作视角出发,提出通过组建聋儿游戏群体,增进聋儿家长社会资本,重构聋儿社会资本的建议。