Improving zero-shot retrieval using dense external expansion

Pseudo-relevance feedback (PRF) is a classical technique to improve search engine retrieval effectiveness, by closing the vocabulary gap between users’ query formulations and the relevant documents. While PRF is typically applied on the same target corpus as the final retrieval, in the past, external expansion techniques have sometimes been applied to obtain a high-quality pseudo-relevant feedback set using the external corpus. However, such external expansion approaches have only been studied for sparse (BoW) retrieval methods, and its effectiveness for recent dense retrieval methods remains under-investigated. Indeed, dense retrieval approaches such as ANCE and ColBERT, which conduct similarity search based on encoded contextualised query and document embeddings, are of increasing importance. Moreover, pseudo-relevance feedback mechanisms have been proposed to further enhance dense retrieval effectiveness. In particular, in this work, we examine the application of dense external expansion to improve zero-shot retrieval effectiveness, i.e. evaluation on corpora without further training. Zero-shot retrieval experiments with six datasets, including two TREC datasets and four BEIR datasets, when applying the MSMARCO passage collection as external corpus, indicate that obtaining external feedback documents using ColBERT can significantly improve NDCG@10 for the sparse retrieval (by upto 28%) and the dense retrieval (by upto 12%). In addition, using ANCE on the external corpus brings upto 30% NDCG@10 improvements for the sparse retrieval and upto 29% for the dense retrieval.     

Enhancing query translation with relevance feedback in translingual information retrieval

As an effective technique for improving retrieval effectiveness, relevance feedback (RF) has been widely studied in both monolingual and translingual information retrieval (TLIR). The studies of RF in TLIR have been focused on query expansion (QE), in which queries are reformulated before and/or after they are translated. However, RF in TLIR actually not only can help select better query terms, but also can enhance query translation by adjusting translation probabilities and even resolving some out-of-vocabulary terms. In this paper, we propose a novel relevance feedback method called translation enhancement (TE), which uses the extracted translation relationships from relevant documents to revise the translation probabilities of query terms and to identify extra available translation alternatives so that the translated queries are more tuned to the current search. We studied TE using pseudo-relevance feedback (PRF) and interactive relevance feedback (IRF). Our results show that TE can significantly improve TLIR with both types of relevance feedback methods, and that the improvement is comparable to that of query expansion. More importantly, the effects of translation enhancement and query expansion are complementary. Their integration can produce further improvement, and makes TLIR more robust for a variety of queries.     

黄土高原社会-生态系统变化及其可持续性

在全球变化和人类活动驱动下,社会系统与生态系统均处在不断加剧的动态变化中,揭示二者之间的互馈机制是保持和增强系统弹性以及可持续性的科学基础。黄土高原地区是中国人口、资源、环境矛盾最集中的区域之一,也是黄河重要的产水区和绝大部分泥沙的来源区。合理布局黄土高原土地利用格局,协调黄土高原水土保持和黄河下游水资源利用与泥沙控制,是黄土高原地区和黄河流域可持续发展的重大需求。本文立足于国际社会-生态系统耦合研究前沿和可持续发展与生态建设的国家需求,综述了区域社会系统与生态系统的互馈机制和社会-生态系统的耦合模拟的研究进展,总结了黄土高原社会-生态系统的变化过程和驱动机制,认为发展社会-生态系统动态机制分析方法和稳态转换识别方法,建立耦合社会系统与生态系统的土地利用权衡与优化模型,是推动社会-生态系统耦合研究理论与方法创新、为黄土高原的可持续发展提供科学依据的重要途径。     

情报学反馈理论及模型：认知观和情境观视角

介绍了控制论和社会科学中的反馈理论和模型以及情报学现有的反馈思想,在此基础上,指出情报学应该具有自己特殊的反馈理论及模型,而不是简单地搬用其他学科的反馈理论和模型。文章认为认知观和情境观是建立情报学反馈理论及模型的基石。建立基于认知观和情境观的情报学反馈理论,并对二者进行了统一。以情报分析这一具体领域为例,分析基于认知观和情境观的情报学反馈模型。     

数字图书馆中的检索结果聚类和关联推荐研究

探讨如何在数字图书馆的文献检索平台中集成实现检索结果聚类、相关文献的关联推荐、相关作者和研究机构的关联推荐以及相关词语的关联推荐,由此帮助用户全面提高查准率和查全率,并且对聚类和推荐结果采用图形进行可视化展示,进一步提高用户的使用满意度。     

E-Mail Reference Evaluation

Abstract

E-mail reference has been utilized as a reference tool in academic libraries since the early 1980s. Today it is one of the most common media for providing digital reference service. An important aspect of providing any service is evaluating users' satisfaction levels with that service. Users of the Ask-A-Librarian e-mail reference service at a large academic library over a ten-month period voluntarily completed a seven item web-based questionnaire. The results indicated that the majority of respondents were satisfied with Ask-A-Librarian overall. This paper discusses how the library used the survey results to improve the existing service, and to implement a new one-chat reference. Reference service providers should not only ask users for feedback on existing services, but also should include them in the planning and design phase of new services. In doing so, they demonstrate their commitment to providing adequate and appropriate services to their patron community, and ultimately can save their institutions time and expense.     

关于学生对高校《金融英语》课程反馈的分析及启示

本文通过对重庆工商大学融智学院金融系高年级学生对《金融英语》课程的教学反馈,对于评教结果进行分析了解《金融英语》在高校的教学质量现状,提出影响学生满意度的主要因素。并对将来《金融英语》的教学工作找到提高的途径,提出相应教改意见。     

Formative assessment: the role of participatory action research in blending policy and practice in Uganda

This paper documents teachers’ assessment practices and pupils’ learning to read and write in large classes. To gain insights into the assessment practices and pupils’ learning, the principles of Vygotsky’s zone of proximal development and participatory action research (PAR) design were adopted. Collaboratively, teachers reflected on their assessment practices, developed, implemented and monitored the assessment practices. Through observation, in-depth interview and review of exercise books, data were obtained. We argue that teachers’ involvement in PAR has contributed to changing assessment practices in large classes and in improving pupils’ competencies in reading and writing. On the other hand to promote better assessment practices, we advocate for reduced number of pupils in a class and teachers’ workload to enable them offer more support to the pupils during assessment of reading and writing.     

构建二级学院教学信息快速反馈体系探索与实践

加强二级学院本科教学质量监控体系建设,是整个本科教学质量监控保障体系的基础性工作。而其中准确地收集、掌握二级学院教学进程中教与学的基本状态数据,及时了解每个教师的教学情况、学生学习的动态是实现二级学院教学管理调控的前提,也是实现过程管理重要的工作。本文结合二级学院教学管理的实际,在构建快速、准确和有效的教学信息收集、处理和调控体系建设方面进行了有益的尝试,通过应用现代通信技术和学生信息员制度,努力体现以学生为本的管理思想,提高教学管理的效率和建立快速反应机制,最终达到提高教学质量目标。     

Ten Years of Puzzling about Audience Awareness

The decisions evaluators make regarding how to work with teachers through the annual evaluation process can have a positive impact on teacher growth and student learning. In this article, the author examines the quality of feedback and how administrators use and provide this feedback to teachers through the evaluation process. What constitutes quality feedback? How does quality feedback support teachers' instruction? How can the supervision and evaluation process offer both teachers and administrators an opportunity to work together to improve student learning? The evaluation process should support the goal of maintaining a high level of quality instruction. In the end, the goal is to increase student learning by improving the effectiveness of teaching.