Impact Factors and the Central Limit Theorem: Why citation averages are scale dependent

Citation averages, and Impact Factors (IFs) in particular, are sensitive to sample size. Here, we apply the Central Limit Theorem to IFs to understand their scale-dependent behavior. For a journal of n randomly selected papers from a population of all papers, we expect from the Theorem that its IF fluctuates around the population average μ, and spans a range of values proportional to $\sigma /\sqrt{n}$, where σ² is the variance of the population's citation distribution. The $1/\sqrt{n}$ dependence has profound implications for IF rankings: The larger a journal, the narrower the range around μ where its IF lies. IF rankings therefore allocate an unfair advantage to smaller journals in the high IF ranks, and to larger journals in the low IF ranks. As a result, we expect a scale-dependent stratification of journals in IF rankings, whereby small journals occupy the top, middle, and bottom ranks; mid-sized journals occupy the middle ranks; and very large journals have IFs that asymptotically approach μ. We obtain qualitative and quantitative confirmation of these predictions by analyzing (i) the complete set of 166,498 IF & journal-size data pairs in the 1997–2016 Journal Citation Reports of Clarivate Analytics, (ii) the top-cited portion of 276,000 physics papers published in 2014–2015, and (iii) the citation distributions of an arbitrarily sampled list of physics journals. We conclude that the Central Limit Theorem is a good predictor of the IF range of actual journals, while sustained deviations from its predictions are a mark of true, non-random, citation impact. IF rankings are thus misleading unless one compares like-sized journals or adjusts for these effects. We propose the Φ index, a rescaled IF that accounts for size effects, and which can be readily generalized to account also for different citation practices across research fields. Our methodology applies to other citation averages that are used to compare research fields, university departments or countries in various types of rankings.     

Dimensions: A competitor to Scopus and the Web of Science?

Dimensions is a partly free scholarly database launched by Digital Science in January 2018. Dimensions includes journal articles and citation counts, making it a potential new source of impact data. This article explores the value of Dimensions from an impact assessment perspective with an examination of Food Science research 2008–2018 and a random sample of 10,000 Scopus articles from 2012. The results include high correlations between citation counts from Scopus and Dimensions (0.96 by narrow field in 2012) as well as similar average counts. Almost all Scopus articles with DOIs were found in Dimensions (97% in 2012). Thus, the scholarly database component of Dimensions seems to be a plausible alternative to Scopus and the Web of Science for general citation analyses and for citation data in support of some types of research evaluations.     

科学过程技能的性别差异

本研究运用表现性评价方式评价科学过程技能,结果发现男女学生的总体科学过程技能不存在差异,但除找出变量之外,其他各过程技能均存在差异。最后,针对这种性别差异讨论了相应的教学和评价建议。     

European standards for quality assurance and institutional practices of student assessment in the UK,the Netherlands and the Czech Republic

This article analyses the student assessment procedures of 12 universities in the UK, the Netherlands and the Czech Republic with respect to their alignment with the European standards and guidelines on the quality of assessing higher education students (European Standards and Guidelines for Quality Assurance [ESG] 1.3). Based on qualitative methodology combining document review with semi-structured interviews, the analysis has yielded three major results. First, the assessment procedures of the UK universities studied indicate the highest alignment with the ESG 1.3 when compared to the Czech institutions, with the Dutch universities occupying the middle ground. Second, a preference for summative assessment to account for pressures of massification can be observed at institutions in all three countries. Third, it is argued that contrary to some (ministerial) expectations, the influence of the ESG on institutions seems to be insignificant, due to unawareness of the ESG 1.3 at all of the UK and Dutch universities analysed and only moderate knowledge of ESG 1.3 in the Czech case. For this reason, there seems to be a need for communicating the ESG to higher education institutions rather than revising the scope of the ESG as envisaged in the 2012 Bologna policy document (Bucharest Communiqué).     

高校文科专业文献学教学的反思

针对文献学课程作为选修课常常受到文献检索等课程的挤压,作为必修课又受到教学对象主、客观两方面因素的制约的情况,提出文献学对于文史哲等专业的治学研究有指导作用,对于学生知识体系的建构和完善有着非同一般的意义,应该成为文科专业的基础课。改进文献学的教学现状,教师必须注意文献学观念的转变,注意与国学教育相融合,提升自己的学术含量,提高自己的文化品格,实现教学策略的调整。     

新时期高校档案的服务创新

新形势下高校档案服务社会化全面展开，促使高校档案馆必须树立新的服务理念，创新服务模式，改进服务手段，革新评价体系。本文基于高校档案管理服务创新理念，提出档案服务创新方法，用服务质量评估衡量高校档案服务是否到位，促进高校档案馆合理生存，顺向发展。     

Formative Assessment: A Meta‐Analysis and a Call for Research

An effect size of about .70 (or .40–.70) is often claimed for the efficacy of formative assessment, but is not supported by the existing research base. More than 300 studies that appeared to address the efficacy of formative assessment in grades K‐12 were reviewed. Many of the studies had severely flawed research designs yielding uninterpretable results. Only 13 of the studies provided sufficient information to calculate relevant effect sizes. A total of 42 independent effect sizes were available. The median observed effect size was .25. Using a random effects model, a weighted mean effect size of .20 was calculated. Moderator analyses suggested that formative assessment might be more effective in English language arts (ELA) than in mathematics or science, with estimated effect sizes of .32, .17, and .09, respectively. Two types of implementation of formative assessment, one based on professional development and the other on the use of computer‐based formative systems, appeared to be more effective than other approaches, yielding mean effect size of .30 and .28, respectively. Given the wide use and potential efficacy of good formative assessment practices, the paucity of the current research base is problematic. A call for more high‐quality studies is issued.     

Elementary school children’s understanding of science: The implementation of an extracurricular science intervention

The promotion of students’ achievement and competence in the so-called STEM disciplines is one cornerstone of current educational research and practice. In particular, as early as elementary school, the fostering of an adequate understanding of science is a normative goal of science education. It facilitates students’ science learning and enables them to understand the nature and development of scientific knowledge. Based on the relevance of the promotion of young children’s understanding of science, a corresponding science intervention was recently developed and successfully evaluated in a first study under highly controlled conditions. The goal of the present study was to investigate the effectiveness of this intervention when implemented in practice. One hundred seventeen third- and fourth-grade students and 10 trained course instructors participated in this study. We applied a randomized block design with waitlist control groups and repeated measures. The results revealed that children assigned to the intervention compared with children assigned to the waitlist control group showed better inquiry-related methodological competencies (a better understanding of the scientific inquiry cycle and experimentation strategies) and a higher need for cognition. The findings point to the successful implementation of the intervention and are compared with the results of the first study.     

VLOOKUP函数在学生体质健康评价中的应用研究

通过对Excel中VLOOKUP函数进行剖析,以学生体质健康评价为例,对VLOOKU函数进行调用实验。研究发现VLOOKUP函数可以有效提高学生体质健康评价的准确性和工作效率。但在应用时务必正确设置函数参数,避免出现批量错误。另外,VLOOKUP函数灵活性较大,应用时人为误差和失误率会加大,专业、人性、智能的学生体质健康评价软件需进一步普及推广。     

Aiming for autonomy: formative peer assessment in a final-year undergraduate course

This article takes a dual focus on the theme of student formative peer assessment. On the one hand it offers a thorough literature review in this field, while on the other it unpacks a case study of curriculum design where peer assessment has been adopted. The practical example draws on recent changes made to a third- and final-year undergraduate research dissertation course in a UK architectural school. Although peer assessment worked quite well in this small setting, similar findings might be uncovered when scaled up to larger cohorts, as well as other disciplines and year groups. The research findings are certainly relevant for other contexts. Qualitative research from a focus group with six students on the course informs the empirical body of the paper. Through engaging with students’ reflections, as well as the relevant literature, and reflexively looking at the curriculum changes, this paper discusses some of the benefits and drawbacks that can arise from peer assessment in this context. Peer assessment is not without its challenges and hiccups, but, despite these, the benefit to autonomous critical thinking cannot be understated. And arguably peer assessment is especially germane for final-year undergraduates as they embark on employment or more advanced studies.