Trial Size for Near-Optimal Choice Between Surveillance and Aggressive Treatment: Reconsidering MSLT-II

Abstract

A convention in designing randomized clinical trials has been to choose sample sizes that yield specified statistical power when testing hypotheses about treatment response. Manski and Tetenov recently critiqued this convention and proposed enrollment of sufficiently many subjects to enable near-optimal treatment choices. This article develops a refined version of that analysis applicable to trials comparing aggressive treatment of patients with surveillance. The need for a refined analysis arises because the earlier work assumed that there is only a primary health outcome of interest, without secondary outcomes. An important aspect of choice between surveillance and aggressive treatment is that the latter may have side effects. One should then consider how the primary outcome and side effects jointly determine patient welfare. This requires new analysis of sample design. As a case study, we reconsider a trial comparing nodal observation and lymph node dissection when treating patients with cutaneous melanoma. Using a statistical power calculation, the investigators assigned 971 patients to dissection and 968 to observation. We conclude that assigning 244 patients to each option would yield findings that enable suitably near-optimal treatment choice. Thus, a much smaller sample size would have sufficed to inform clinical practice.     

On mitigating collinearity through mixtures

In linear models having near collinear columns of X, ridge and surrogate estimators often are used to mitigate collinearity. A new class of estimators is based on mixtures, either of X and a design minimal in an ordered class or of the Fisher information and a scalar matrix. Comparisons are drawn among choices for the mixing parameter, and the estimators are found to be admissible relative to ordinary least squares. Case studies demonstrate that selected mixture designs are perturbed from the original design to a lesser extent than are those of the surrogate method, while retaining reasonable efficiency characteristics.     

The ISSN as Identifier and as Linking Mechanism: An Interview with Fran§oise Pell©

Abstract

In this installment of Serial conversations, MIT cataloger Benjamin Abrahamse talks with Fran§oise Pell©, head of the International ISSN Centre, about the role played by International Standard Serial Numbers (ISSN) in facilitating the identification and collocation of serial publications in a networked environment.     

Content Audit for p-value Principles in Introductory Statistics

ABSTRACT

Longstanding concerns with the role and interpretation of p-values in statistical practice prompted the American Statistical Association (ASA) to make a statement on p-values. The ASA statement spurred a flurry of responses and discussions by statisticians, with many wondering about the steps necessary to expand the adoption of these principles. Introductory statistics classrooms are key locations to introduce and emphasize the nuance related to p-values; in part because they engrain appropriate analysis choices at the earliest stages of statistics education, and also because they reach the broadest group of students. We propose a framework for statistics departments to conduct a content audit for p-value principles in their introductory curriculum. We then discuss the process and results from applying this course audit framework within our own statistics department. We also recommend meeting with client departments as a complement to the course audit. Discussions about analyses and practices common to particular fields can help to evaluate if our service courses are meeting the needs of client departments and to identify what is needed in our introductory courses to combat the misunderstanding and future misuse of p-values.     

Library Binding

Abstract

Open Data (OD) is an emerging term in the process of defining how scientific data may be published and re-used without price or permission barriers. Scientists generally see published data as belonging to the scientific community, but many publishers claim copyright over data and will not allow its re-use without permission. This is a major impediment to the progress of scholarship in the digital age. This article reviews the need for Open Data, shows examples of why Open Data are valuable, and summarizes some early initiatives in formalizing the right of access to and re-use of scientific data.     

The Missing Model: A “Circle of Gifts”

Abstract

In spite of the search for electronic publishing models, there is apparently already early, energetic scholarly publishing on the networks. Without a great deal of adjustment and even without formal academic recognition, the Net's accessibility and excitement have provided academic "incentives." With thoughtful development, it could provide a highly effective and competitive path to delivering scholarly knowledge. Indeed, there is currently so much momentum that it is difficult to imagine a failure to proceed, short of a deliberate and concerted attempt by universities and scholars to suppress the "thousand flowers" blooming on the scholarly networks, a choice not to support and subsidize academic publishing on the Net.

An effective scholar-based publishing system must recognize and support the widely divers forms of communication necessary for research and scholarship. It should not discriminate against nonlucrative projects or disciplines. It complements the paper-based scholarly efforts of university presses and of academic libraries, which are already beginning to provide networked access and archiving for university-generated scholarship. It creates a linked structure of scholars, societies, and academic institutions. It aims to fulfill another vital objective: retaining for the academy some ownership of its authored intellectual property.

The Missing Model, fledgling and fuzzy, is alive and well and living on the Net. To thrive, the academy needs to thoughtfully nurture it. The Circle of Gifts concept formally entwines the scholarly community, research institutions, scholars, and learned societies in the age-old and time-honored enterprise in which ideas are shared, affordably, by the creators of the ideas.     

Scholarly Communications Training: Professional Development for the Next Generation of Scholars

Abstract

Many campuses are seeing increased needs for support in scholarly communications areas such as open access, research identity management, scholarship metrics, and related topics. This article discusses a professional development program that addresses scholarly communications needs for online and in-person graduate students and faculty at UNC Greensboro (UNCG), through a collaborative, interdepartmental effort that brings together librarians from the departments of Research, Outreach, and Instruction (ROI) and Technical Services. The authors provide a brief overview of the literature related to scholarly communications needs and training in academic libraries and discuss the UNCG program’s inception, modules, format, assessment, and future directions.     

“United we save,divided we spend”: Current purchasing trends in serials acquisitions in the UK academic sector

Abstract

CrossRef is an independent membership association for building shared technologies. It has an unusual mission: to improve access to published scholarship through services that require collective agreement among competitors in scholarly and professional publishing. The CrossRef network today covers millions of articles and other content items from several hundred publishers. This article looks at how far CrossRef has come since it launched in 2000 and what has to happen going forward in order for the service to arrive at a truly comprehensive linking network for scholarly and professional content online. Serial Review 2004; XX: XXX-XXX.     

Electronic Resources Forum - Managing Researcher Identity: Tools for Researchers and Librarians

Abstract

Researchers have increasing opportunities to identify themselves and raise the profile of their research and scholarship through online researcher identity management and researcher profile systems. This column provides a basic introduction to researcher identity management and examines four widely used researcher profile systems: Google Scholar Citations, Open Researcher and Contributor Identifier (ORCID), Scopus Author ID, and Web of Science ResearcherID. System benefits and comparisons are provided, with the purpose of helping researchers and librarians to select appropriate researcher identity management tools to support their work.     

The generalized kullback-leibler divergence and robust inference

This paper examines robust techniques for estimation and tests of hypotheses using the family of generalized Kullback-Leibler (GKL) divergences. The GKL family is a new group of density based divergences which forms a subclass of disparities defined by Lindsay (1994). We show that the corresponding minimum divergence estimators have a breakdown point of 50% under the model. The performance of the proposed estimators and tests are investigated through an extensive numerical study involving real-data examples and simulation results. The results show that the proposed methods are attractive choices for highly efficient and robust methods.     

城镇劳动力市场城乡分割的程度与特征 ——基于浙江数据的经验研究

 劳动力市场的城乡分割意味着经济效率的损失，一直来备受关注。本文构建了一个劳动力市场城乡分割指数，基于中国城镇住户调查浙江省的数据，测量了城镇劳动力市场城乡分割的程度。结果显示：在工资回报层面，相对高端领域的分割程度弱于相对低端领域，但在就业机会层面，相对高端领域的分割程度强于相对低端领域。为此我们建议：劳动力市场管理上重点关注低端劳动力市场中城乡劳动者的同工同酬问题，公共政策设计上重点关注高端劳动力市场中城乡劳动力的平等就业机会问题。     

Behrens-Fisher问题的正态逼近

 本文提出用基于得分检验的正态逼近方法来解决Behrens-Fisher问题，即比较方差比未知时两正态总体的均值。模拟结果显示：在所有的研究情况下，我们的方法都能很好地控制第一类错误，检验功效也不差；而最常用的Welch近似t检验在样本量不等时大多数情况都不能控制第一类错误。     

Great River Review

Abstract

It will soon be rare for research-based institutions not to have a digital repository. The main reason for a repository is to maximize the visibility of the institution’s research outputs (provide Open Access), yet few contain a representative proportion of the research produced by their institutions. Repositories form one part of the institution’s Web platform. An explicit, mandatory policy on the use of the repository for collecting outputs is needed in every institution so that the full research record is collected. Once full, a repository is a tool that enables senior management in research institutions to collate and assess research, to market their institution, to facilitate new forms of scholarship, and to enable the tools that will produce new knowledge.     

CPI编制及公布的国际比较

 本文在参考国际组织所提出的关于CPI的规范的基础上，同时参考了一些国家在统计实践中的做法，对中国CPI的编制及公布进行了国际比较，分析了所存在的差距，并提出了几点结论及建议。     

Bibliometrics: Understanding Author-, Article- and Journal-Level Metrics

ABSTRACT

Numerous types of metrics are available to assist in the evaluation of scholarship. The focus for this column of In Lay Terms is bibliometrics, the quantitative analysis of publication data using article-, author-, and journal-level data. Citation analysis is the most commonly used bibliometric method. It includes analyzing the number of articles published by an author, the number of citations from those articles, and the ranking of the journals in which those articles were published. This column compares bibliometrics found in Web of Science, Scopus, and Google Scholar and considers the relationship of these metrics to the field of library and information science.     

关于我国统计指标消除季节因素影响方法的探讨

 从方法论上说，我国统计指标的季节调整问题关键在于公历数据的农历化，唯有如此才能消除农历的季节因素影响，舍此并无其他与经济发达国家不同的地方，至于对消除了农历的季节因素影响后的数据的处理，尽可采取诸如X12之类的方法程序。但无论是数据的农历化过程还是消除农历季节因素的影响，都有若干方法可以选择，笔者认为趋势分摊法的数据农历化过程配以固定季节因子法消除农历季节因素的方案是最合适的。     

我国国内资本流动的结构性变迁研究

一、引言在一个封闭的宏观经济中 ,投资主要来源于储蓄 ,并且事后的实际投资总量等于事后的实际储蓄总量 ,此时财政政策和货币政策对私人投资和消费有完全的影响 ,任何可观察到的储蓄增长意味着投资的增加。但在一个开放经济中 ,对经济的每一个地区或部门 ,储蓄和投资并不相等 ,储蓄和投资之间会出现不平衡缺口 ,资本便在不同地区和部门之间流动 ,此时财政政策和货币政策的效果要受到资本流动的影响 ,如果不平衡缺口小 ,储蓄结构直接制约投资结构 ,如果缺口大 ,储蓄结构只能通过资本流动间接影响投资结构。储蓄投资的不平衡缺口的出现有多种…