11 research outputs found

    When to stop making relevance judgments? A study of stopping methods for building information retrieval test collections

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    This is the peer reviewed version of the following article: David E. Losada, Javier Parapar and Alvaro Barreiro (2019) When to Stop Making Relevance Judgments? A Study of Stopping Methods for Building Information Retrieval Test Collections. Journal of the Association for Information Science and Technology, 70 (1), 49-60, which has been published in final form at https://doi.org/10.1002/asi.24077. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsIn information retrieval evaluation, pooling is a well‐known technique to extract a sample of documents to be assessed for relevance. Given the pooled documents, a number of studies have proposed different prioritization methods to adjudicate documents for judgment. These methods follow different strategies to reduce the assessment effort. However, there is no clear guidance on how many relevance judgments are required for creating a reliable test collection. In this article we investigate and further develop methods to determine when to stop making relevance judgments. We propose a highly diversified set of stopping methods and provide a comprehensive analysis of the usefulness of the resulting test collections. Some of the stopping methods introduced here combine innovative estimates of recall with time series models used in Financial Trading. Experimental results on several representative collections show that some stopping methods can reduce up to 95% of the assessment effort and still produce a robust test collection. We demonstrate that the reduced set of judgments can be reliably employed to compare search systems using disparate effectiveness metrics such as Average Precision, NDCG, P@100, and Rank Biased Precision. With all these measures, the correlations found between full pool rankings and reduced pool rankings is very highThis work received financial support from the (i) “Ministerio de Economía y Competitividad” of the Government of Spain and FEDER Funds under the researchproject TIN2015-64282-R, (ii) Xunta de Galicia (project GPC 2016/035), and (iii) Xunta de Galicia “Consellería deCultura, Educación e Ordenación Universitaria” and theEuropean Regional Development Fund (ERDF) throughthe following 2016–2019 accreditations: ED431G/01(“Centro singular de investigación de Galicia”) andED431G/08S

    Predictive Coding Techniques with Manual Review to Identify Privileged Documents in E-Discovery

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    In twenty-first century civil litigation, discovery focuses on the retrieval of electronically stored information. Lawsuits may be won or lost because of incorrect production of electronic evidence. Organizations may generate fewer paper documents, leading to an increase in the amount of electronic documents by many fold. Litigants face the task of searching millions of electronic records for the presence of responsive and not-privileged documents, making the e-discovery process burdensome and expensive. In order to ensure that the material that has to be withheld is not inadvertently revealed, the electronic evidence that is found to be responsive to a production request is typically subjected to an exhaustive manual review for privilege. Although the budgetary constraints on review for responsiveness can be met using automation to some degree, attorneys have been hesitant to adopt similar technology to support the privilege review process. This dissertation draws attention to the potential for adopting predictive coding technology for the privilege review phase during the discovery process. Two main questions that are central to building a privilege classifier are addressed. The first question seeks to determine which set of annotations can serve as a reliable basis for evaluation. The second question seeks to determine which of the remaining annotations, when used for training classifiers, produce the best results. As an answer, binary classifiers are trained on labeled annotations from both junior and senior reviewers. Issues related to training bias and sample variance due to the reviewer's expertise are thoroughly discussed. Results show that the annotations that were randomly drawn and annotated by senior reviewers are useful for evaluation. The remaining annotations can be used for classifier training. A research prototype is built to perform a user study. Privilege judgments are gathered from multiple lawyers using two user interfaces. One of the two interfaces includes automatically generated features to aid the review process. The goal is to help lawyers make faster and more accurate privilege judgments. A significant improvement in recall was noted when comparing the users' review performance when using the automated annotations. Classifier features related to the people involved in privileged communications were found to be particularly important for the privilege review task. Results show that there was no measurable change in review time. As cost is proportional to time during review, as the final step, this work introduces a semi-automated framework that aims to optimize the cost of the manual review process. The framework calls for litigants to make some rational choices about what to manually review. The documents are first automatically classified for responsiveness and privilege, and then some of the automatically classified documents are reviewed by human reviewers for responsiveness and for privilege with the overall goal of minimizing the expected cost of the entire process, including costs that arise from incorrect decisions. A risk-based ranking algorithm is used to determine which documents need to be manually reviewed. Multiple baselines are used to characterize the cost savings achieved by this approach. Although the work in this dissertation is applied to e-discovery, similar approaches could be applied to any case in which retrieval systems have to withhold a set of confidential documents despite their relevance to the request

    Techniques for Improving Web Search by Understanding Queries

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    This thesis investigates the refinement of web search results with a special focus on the use of clustering and the role of queries. It presents a collection of new methods for evaluating clustering methods, performing clustering effectively, and for performing query refinement. The thesis identifies different types of query, the situations where refinement is necessary, and the factors affecting search difficulty. It then analyses hard searches and argues that many of them fail because users and search engines have different query models. The thesis identifies best practice for evaluating web search results and search refinement methods. It finds that none of the commonly used evaluation measures for clustering meet all of the properties of good evaluation measures. It then presents new quality and coverage measures that satisfy all the desired properties and that rank clusterings correctly in all web page clustering situations. The thesis argues that current web page clustering methods work well when different interpretations of the query have distinct vocabulary, but still have several limitations and often produce incomprehensible clusters. It then presents a new clustering method that uses the query to guide the construction of semantically meaningful clusters. The new clustering method significantly improves performance. Finally, the thesis explores how searches and queries are composed of different aspects and shows how to use aspects to reduce the distance between the query models of search engines and users. It then presents fully automatic methods that identify query aspects, identify underrepresented aspects, and predict query difficulty. Used in combination, these methods have many applications — the thesis describes methods for two of them. The first method improves the search results for hard queries with underrepresented aspects by automatically expanding the query using semantically orthogonal keywords related to the underrepresented aspects. The second method helps users refine hard ambiguous queries by identifying the different query interpretations using a clustering of a diverse set of refinements. Both methods significantly outperform existing methods

    Modeling user information needs on mobile devices: from recommendation to conversation

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    Recent advances in the development of mobile devices, equipped with multiple sensors, together with the availability of millions of applications have made these devices more pervasive in our lives than ever. The availability of the diverse set of sensors, as well as high computational power, enable information retrieval (IR) systems to sense a user’s context and personalize their results accordingly. Relevant studies show that people use their mobile devices to access information in a wide range of topics in various contextual situations, highlighting the fact that modeling user information need on mobile devices involves studying several means of information access. In this thesis, we study three major aspects of information access on mobile devices. First, we focus on proactive approaches to modeling users for venue suggestion. We investigate three methods of user modeling, namely, content-based, collaborative, and hybrid, focusing on personalization and context-awareness. We propose a two-phase collaborative ranking algorithm for leveraging users’ implicit feedback while incorporating temporal and geographical information into the model. We then extend our collaborative model to include multiple cross-venue similarity scores and combine it with our content-based approach to produce a hybrid recommendation. Second, we introduce and investigate a new task on mobile search, that is, unified mobile search. We take the first step in defining, studying, and modeling this task by collecting two datasets and conducting experiments on one of the main components of unified mobile search frameworks, that is target apps selection. To this end, we propose two neural approaches. Finally, we address the conversational aspect of mobile search where we propose an offline evaluation protocol and build a dataset for asking clarifying questions for conversational search. Also, we propose a retrieval framework consisting of three main components: question retrieval, question selection, and document retrieval. The experiments and analyses indicate that asking clarifying questions should be an essential part of a conversational system, resulting in high performance gain

    Causal reasoning in the diagnosis of mental disorders: Evidence from on-line and off-line measures

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    En esta serie experimental se demuestra que el diagnóstico de los trastornos mentales no se atiene de forma estricta a los criterios diagnósticos del DSM-IV, sino que está sesgado por teorías y creencias causales. Además, probamos que, en este sesgo causal, tienen una implicación importante procesos de razonamiento intuitivo, rápidos y automáticos (o semiautomáticos), atribuibles a lo que se conoce como sistema 1

    Tätigkeitsbericht 2005-2006

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    Pertanika Journal of Social Sciences & Humanities

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    Ill. teach. home econ. (1973)

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    Description based on: Vol. 17, no. 2 (Nov.-Dec. 1973); title from cover.Education index 0013-1385 -1992Current index to journals in education 0011-3565Bibliography of agriculture 0006-153

    Annual Report

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