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.     

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.     

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.     

A Design of Attributes Double Sampling Plans for Three-class Products

In this article, a new attributes double sampling plan for three-class products (ADSPTP) is presented, and the corresponding operating characteristic function is constructed based on the given procedure of performing ADSPTP. Average sample numbers (ASN) for complete inspection and curtailed inspection of the second sample are derived and the extreme point is discussed on the three-dimensional ASN surface. In addition, the differences arising from different parameters are studied. Sampling plans are designed by a nonlinear optimization model. Finally, numerical examples and discussions are given to illustrate the obtained results, and tables of the designed plans under various conditions are provided.     

INFORMATION-CENTRED DESIGN: A methodology for designing virtual meeting DESIGN environments

Development of single-user computer applications has often been based on user-centred or task-centred design methodologies, with some success. These methodologies are also useful for guiding the development of multi-user CSCW applications whenever the basic characteristics of the users, or the type of tasks for which the system is being designed are identifiable. The effectiveness of these methodologies as a basis for the design of virtual meeting environments for supporting community-based activities, on the other hand, is rather limited. This is mainly due to the fact that for such systems it is not generally possible to identify the user or task requirements, as these vary considerably from one community to another, or even within the same community over a period of time. New methodologies need to be devised, or existing methodologies have to be modified, to direct the development of virtual environments for which the characteristics of the users or their activities are not known in advance. This paper introduces the concept of information-centred design. Information-centred design, though not fully devised yet, focuses on the identification of the type of information, as well as the way it is collected and utilized by the users of a virtual meeting environment. This pool of information, which plays an important role in facilitating interaction and communication between the members of a community, could be defined as their communal memory.     

工地政体：建筑女工群体形成原因探析

建筑工地中不乏女工身影,34％份额的女工分布于各个工种,但在技术和权力分层上女工占劣势地位,导致建筑女工群体被忽视。基于工地政体四个要素：劳动过程、劳动力再生产、国家和市场,文章从个人、家庭、建筑行业特性和社会形势背景四个方面探讨建筑女工群体形成的原因。     

Comparative Analysis of Distance Education and Classroom-based Formats for a Clinical Social Work Practice Course

A growing body of research suggests that online courses are as effective as face-to-face courses in delivering knowledge-based content. Scant research, however, has been conducted to examine the usefulness of distance education (DE) for teaching clinical coursework. This study compared the outcomes of students who participated in DE sections of a graduate level Social Work Practice with Groups course with students engaged in traditional face-to-face sections of the same course. The DE sections were primarily online and used asynchronistic and synchronistic technology coupled with a few Saturday sessions. Results revealed no significant differences between DE and in-class students in knowledge of leadership skills, group processes and dynamics, or perception of course content and effectiveness. Implications for social work education are discussed.     

Determining Differences in Expert Judgment: Implications for Knowledge Acquisition and Validation*

In knowledge acquisition, it is often desirable to aggregate the judgments of multiple experts into a single system. In some cases this takes the form of averaging the judgments of those experts. In these situations it is desirable to determine if the experts have different views of the world before their individual judgments are aggregated. In validation, multiple experts often are employed to compare the performance of expert systems and other human actors. Often those judgments are then averaged to establish performance quality of the expert system. An important part of the comparison process should be determining if the experts have a similar view of the world. If the experts do not have similar views, their evaluations of performance may differ, resulting in a meaningless average performance measure. Alternatively, if all the validating experts do have similar views of the world then the validation process may result in paradigm myopia.     

Redesigning a Cellular Manufacturing System to Handle Long-Term Demand Changes: A Methodology and Investigation*

Cellular manufacturing systems have been proposed as an alternative to the job shop since they provide some of the operational benefits of a flow line production process, while retaining to some extent the flexibility of job shops. However, this must be balanced against the possibility of additional initial investments in equipment to form the cells and a certain loss in manufacturing flexibility, particularly in terms of the ability to deal with long-term demand changes. This paper presents a model-based heuristic cell system redesign methodology to deal with such demand changes. The methodology is validated and applied to system designs generated from several data sets published in the literature. Results show that different kinds of demand changes incur distinct kinds of costs. Further, characteristics of cell designs that can handle long-term demand changes at least cost are identified.