Jiyin He, M. Bron, A. D. Vries, L. Azzopardi, M. de Rijke
Traditional batch evaluation metrics assume that user interaction with search results is limited to scanning down a ranked list. However, modern search interfaces come with additional elements supporting result list refinement (RLR) through facets and filters, making user search behavior increasingly dynamic. We develop an evaluation framework that takes a step beyond the interaction assumption of traditional evaluation metrics and allows for batch evaluation of systems with and without RLR elements. In our framework we model user interaction as switching between different sublists. This provides a measure of user effort based on the joint effect of user interaction with RLR elements and result quality. We validate our framework by conducting a user study and comparing model predictions with real user performance. Our model predictions show significant positive correlation with real user effort. Further, in contrast to traditional evaluation metrics, the predictions using our framework, of when users stand to benefit from RLR elements, reflect findings from our user study. Finally, we use the framework to investigate under what conditions systems with and without RLR elements are likely to be effective. We simulate varying conditions concerning ranking quality, users, task and interface properties demonstrating a cost-effective way to study whole system performance.
{"title":"Untangling Result List Refinement and Ranking Quality: a Framework for Evaluation and Prediction","authors":"Jiyin He, M. Bron, A. D. Vries, L. Azzopardi, M. de Rijke","doi":"10.1145/2766462.2767740","DOIUrl":"https://doi.org/10.1145/2766462.2767740","url":null,"abstract":"Traditional batch evaluation metrics assume that user interaction with search results is limited to scanning down a ranked list. However, modern search interfaces come with additional elements supporting result list refinement (RLR) through facets and filters, making user search behavior increasingly dynamic. We develop an evaluation framework that takes a step beyond the interaction assumption of traditional evaluation metrics and allows for batch evaluation of systems with and without RLR elements. In our framework we model user interaction as switching between different sublists. This provides a measure of user effort based on the joint effect of user interaction with RLR elements and result quality. We validate our framework by conducting a user study and comparing model predictions with real user performance. Our model predictions show significant positive correlation with real user effort. Further, in contrast to traditional evaluation metrics, the predictions using our framework, of when users stand to benefit from RLR elements, reflect findings from our user study. Finally, we use the framework to investigate under what conditions systems with and without RLR elements are likely to be effective. We simulate varying conditions concerning ranking quality, users, task and interface properties demonstrating a cost-effective way to study whole system performance.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132957416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Information retrieval systems rank documents, and shared-task evaluations yield results that can be used to rank information retrieval systems. Comparing rankings in ways that can yield useful insights is thus an important capability. When making such comparisons, it is often useful to give greater weight to comparisons near the head of a ranked list than to what happens further down. This is the focus of the widely used τAP measure. When scores are available, gap-sensitive measures give greater weight to larger differences than to smaller ones. This is the focus of the widely used Pearson correlation measure (ρ). This paper introduces a new measure, τGAP, which combines both features. System comparisons from the TREC 5 Ad Hoc track are used to illustrate the differences in emphasis achieved by τAP, ρ, and the proposed τGAP.
信息检索系统对文档进行排序,共享任务评估产生的结果可用于对信息检索系统进行排序。因此,以能够产生有用见解的方式比较排名是一项重要的功能。在进行这种比较时,给予排名列表顶部附近的比较更大的权重,而不是后面发生的比较,通常是有用的。这是广泛使用的τAP度量的重点。当分数可用时,差距敏感指标给予较大差异比较小差异更大的权重。这是广泛使用的Pearson相关度量(ρ)的焦点。本文介绍了一种结合这两个特征的新测度τGAP。来自TREC 5 Ad Hoc轨道的系统比较用于说明τAP, ρ和提出的τGAP在重点上的差异。
{"title":"A Head-Weighted Gap-Sensitive Correlation Coefficient","authors":"Ning Gao, Douglas W. Oard","doi":"10.1145/2766462.2767793","DOIUrl":"https://doi.org/10.1145/2766462.2767793","url":null,"abstract":"Information retrieval systems rank documents, and shared-task evaluations yield results that can be used to rank information retrieval systems. Comparing rankings in ways that can yield useful insights is thus an important capability. When making such comparisons, it is often useful to give greater weight to comparisons near the head of a ranked list than to what happens further down. This is the focus of the widely used τAP measure. When scores are available, gap-sensitive measures give greater weight to larger differences than to smaller ones. This is the focus of the widely used Pearson correlation measure (ρ). This paper introduces a new measure, τGAP, which combines both features. System comparisons from the TREC 5 Ad Hoc track are used to illustrate the differences in emphasis achieved by τAP, ρ, and the proposed τGAP.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133200263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashraf Bah Rabiou, Praveen Chandar, Ben Carterette
Different users may be attempting to satisfy different information needs while providing the same query to a search engine. Addressing that issue is addressing Novelty and Diversity in information retrieval. Novelty and Diversity search task models the task wherein users are interested in seeing more and more documents that are not only relevant, but also cover more aspects (or subtopics) related to the topic of interest. This is in contrast with the traditional IR task where topical relevance is the only factor in evaluating search results. In this paper, we conduct a user study where users are asked to give a preference between one of two documents B and C given a query and also given that they have already seen a document A. We then test a total of ten hypotheses pertaining to the relationship between the "comprehensiveness" of documents (i.e. the number of subtopics a document is relevant to) and real users' preference judgments. Our results show that users are inclined to prefer documents with higher comprehensiveness, even when the prior document A already covers more aspects than the two documents being compared, and even when the least preferred has a higher relevance grade. In fact, users are inclined to prefer documents with higher overall aspect-coverage even in cases where B and C are relevant to the same number of novel subtopics.
{"title":"Document Comprehensiveness and User Preferences in Novelty Search Tasks","authors":"Ashraf Bah Rabiou, Praveen Chandar, Ben Carterette","doi":"10.1145/2766462.2767820","DOIUrl":"https://doi.org/10.1145/2766462.2767820","url":null,"abstract":"Different users may be attempting to satisfy different information needs while providing the same query to a search engine. Addressing that issue is addressing Novelty and Diversity in information retrieval. Novelty and Diversity search task models the task wherein users are interested in seeing more and more documents that are not only relevant, but also cover more aspects (or subtopics) related to the topic of interest. This is in contrast with the traditional IR task where topical relevance is the only factor in evaluating search results. In this paper, we conduct a user study where users are asked to give a preference between one of two documents B and C given a query and also given that they have already seen a document A. We then test a total of ten hypotheses pertaining to the relationship between the \"comprehensiveness\" of documents (i.e. the number of subtopics a document is relevant to) and real users' preference judgments. Our results show that users are inclined to prefer documents with higher comprehensiveness, even when the prior document A already covers more aspects than the two documents being compared, and even when the least preferred has a higher relevance grade. In fact, users are inclined to prefer documents with higher overall aspect-coverage even in cases where B and C are relevant to the same number of novel subtopics.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"345 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122837049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While watching television, people increasingly consume additional content related to what they are watching. We consider the task of finding video content related to a live television broadcast for which we leverage the textual stream of subtitles associated with the broadcast. We model this task as a Markov decision process and propose a method that uses reinforcement learning to directly optimize the retrieval effectiveness of queries generated from the stream of subtitles. Our dynamic query modeling approach significantly outperforms state-of-the-art baselines for stationary query modeling and for text-based retrieval in a television setting. In particular we find that carefully weighting terms and decaying these weights based on recency significantly improves effectiveness. Moreover, our method is highly efficient and can be used in a live television setting, i.e., in near real time.
{"title":"Dynamic Query Modeling for Related Content Finding","authors":"Daan Odijk, E. Meij, I. Sijaranamual, M. de Rijke","doi":"10.1145/2766462.2767715","DOIUrl":"https://doi.org/10.1145/2766462.2767715","url":null,"abstract":"While watching television, people increasingly consume additional content related to what they are watching. We consider the task of finding video content related to a live television broadcast for which we leverage the textual stream of subtitles associated with the broadcast. We model this task as a Markov decision process and propose a method that uses reinforcement learning to directly optimize the retrieval effectiveness of queries generated from the stream of subtitles. Our dynamic query modeling approach significantly outperforms state-of-the-art baselines for stationary query modeling and for text-based retrieval in a television setting. In particular we find that carefully weighting terms and decaying these weights based on recency significantly improves effectiveness. Moreover, our method is highly efficient and can be used in a live television setting, i.e., in near real time.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123042145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When consuming content in applications such as e-readers, word processors, and Web browsers, users often see mentions to topics (or concepts) that attract their attention. In a scenario of significant practical interest, topics are explored in situ, without leaving the context of the application: The user selects a mention of a topic (in the form of continuous text), and the system subsequently recommends references (e.g., Wikipedia concepts) that are relevant in the context of the application. In order to realize this experience, it is necessary to tackle challenges that include: users may select any continuous text, even potentially noisy text for which there is no corresponding reference in the knowledge base; references must be relevant to both the user selection and the text around it; and the real estate available on the application may be constrained, thus limiting the number of results that can be shown. In this paper, we study this novel recommendation task, that we call in situ insights: recommending reference concepts in response to a text selection and its context in-situ of a document consumption application. We first propose a selection-centric context language model and a selection-centric context semantic model to capture user interest. Based on these models, we then measure the quality of a reference concept across three aspects: selection clarity, context coherence, and concept relevance. By leveraging all these aspects, we put forward a machine learning approach to simultaneously decide if a selection is noisy, and filter out low-quality candidate references. In order to quantitatively evaluate our proposed techniques, we construct a test collection based on the simulation of the in situ insights scenario using crowdsourcing in the context of a real-word e-reader application. Our experimental evaluation demonstrates the effectiveness of the proposed techniques.
{"title":"In Situ Insights","authors":"Yuanhua Lv, A. Fuxman","doi":"10.1145/2766462.2767696","DOIUrl":"https://doi.org/10.1145/2766462.2767696","url":null,"abstract":"When consuming content in applications such as e-readers, word processors, and Web browsers, users often see mentions to topics (or concepts) that attract their attention. In a scenario of significant practical interest, topics are explored in situ, without leaving the context of the application: The user selects a mention of a topic (in the form of continuous text), and the system subsequently recommends references (e.g., Wikipedia concepts) that are relevant in the context of the application. In order to realize this experience, it is necessary to tackle challenges that include: users may select any continuous text, even potentially noisy text for which there is no corresponding reference in the knowledge base; references must be relevant to both the user selection and the text around it; and the real estate available on the application may be constrained, thus limiting the number of results that can be shown. In this paper, we study this novel recommendation task, that we call in situ insights: recommending reference concepts in response to a text selection and its context in-situ of a document consumption application. We first propose a selection-centric context language model and a selection-centric context semantic model to capture user interest. Based on these models, we then measure the quality of a reference concept across three aspects: selection clarity, context coherence, and concept relevance. By leveraging all these aspects, we put forward a machine learning approach to simultaneously decide if a selection is noisy, and filter out low-quality candidate references. In order to quantitatively evaluate our proposed techniques, we construct a test collection based on the simulation of the in situ insights scenario using crowdsourcing in the context of a real-word e-reader application. Our experimental evaluation demonstrates the effectiveness of the proposed techniques.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127862276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Given a topic of interest, a contrastive theme is a group of opposing pairs of viewpoints. We address the task of summarizing contrastive themes: given a set of opinionated documents, select meaningful sentences to represent contrastive themes present in those documents. Several factors make this a challenging problem: unknown numbers of topics, unknown relationships among topics, and the extraction of comparative sentences. Our approach has three core ingredients: contrastive theme modeling, diverse theme extraction, and contrastive theme summarization. Specifically, we present a hierarchical non-parametric model to describe hierarchical relations among topics; this model is used to infer threads of topics as themes from the nested Chinese restaurant process. We enhance the diversity of themes by using structured determinantal point processes for selecting a set of diverse themes with high quality. Finally, we pair contrastive themes and employ an iterative optimization algorithm to select sentences, explicitly considering contrast, relevance, and diversity. Experiments on three datasets demonstrate the effectiveness of our method.
{"title":"Summarizing Contrastive Themes via Hierarchical Non-Parametric Processes","authors":"Z. Ren, M. de Rijke","doi":"10.1145/2766462.2767713","DOIUrl":"https://doi.org/10.1145/2766462.2767713","url":null,"abstract":"Given a topic of interest, a contrastive theme is a group of opposing pairs of viewpoints. We address the task of summarizing contrastive themes: given a set of opinionated documents, select meaningful sentences to represent contrastive themes present in those documents. Several factors make this a challenging problem: unknown numbers of topics, unknown relationships among topics, and the extraction of comparative sentences. Our approach has three core ingredients: contrastive theme modeling, diverse theme extraction, and contrastive theme summarization. Specifically, we present a hierarchical non-parametric model to describe hierarchical relations among topics; this model is used to infer threads of topics as themes from the nested Chinese restaurant process. We enhance the diversity of themes by using structured determinantal point processes for selecting a set of diverse themes with high quality. Finally, we pair contrastive themes and employ an iterative optimization algorithm to select sentences, explicitly considering contrast, relevance, and diversity. Experiments on three datasets demonstrate the effectiveness of our method.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128548986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Session details: Session 4A: User Models","authors":"D. Kelly","doi":"10.1145/3255924","DOIUrl":"https://doi.org/10.1145/3255924","url":null,"abstract":"","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115500573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In information retrieval evaluation, when presented with an effectiveness difference between two systems, there are three relevant questions one might ask. First, are the differences statistically significant? Second, is the comparison stable with respect to assessor differences? Finally, is the difference actually meaningful to a user? This paper tackles the last two questions about assessor differences and user preferences in the context of the newly-introduced tweet timeline generation task in the TREC 2014 Microblog track, where the system's goal is to construct an informative summary of non-redundant tweets that addresses the user's information need. Central to the evaluation methodology is human-generated semantic clusters of tweets that contain substantively similar information. We show that the evaluation is stable with respect to assessor differences in clustering and that user preferences generally correlate with effectiveness metrics even though users are not explicitly aware of the semantic clustering being performed by the systems. Although our analyses are limited to this particular task, we believe that lessons learned could generalize to other evaluations based on establishing semantic equivalence between information units, such as nugget-based evaluations in question answering and temporal summarization.
{"title":"Assessor Differences and User Preferences in Tweet Timeline Generation","authors":"Yulu Wang, G. Sherman, Jimmy J. Lin, Miles Efron","doi":"10.1145/2766462.2767699","DOIUrl":"https://doi.org/10.1145/2766462.2767699","url":null,"abstract":"In information retrieval evaluation, when presented with an effectiveness difference between two systems, there are three relevant questions one might ask. First, are the differences statistically significant? Second, is the comparison stable with respect to assessor differences? Finally, is the difference actually meaningful to a user? This paper tackles the last two questions about assessor differences and user preferences in the context of the newly-introduced tweet timeline generation task in the TREC 2014 Microblog track, where the system's goal is to construct an informative summary of non-redundant tweets that addresses the user's information need. Central to the evaluation methodology is human-generated semantic clusters of tweets that contain substantively similar information. We show that the evaluation is stable with respect to assessor differences in clustering and that user preferences generally correlate with effectiveness metrics even though users are not explicitly aware of the semantic clustering being performed by the systems. Although our analyses are limited to this particular task, we believe that lessons learned could generalize to other evaluations based on establishing semantic equivalence between information units, such as nugget-based evaluations in question answering and temporal summarization.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115571940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Session details: Session 2A: Diversity and Bias","authors":"Gareth J.F. Jones","doi":"10.1145/3255918","DOIUrl":"https://doi.org/10.1145/3255918","url":null,"abstract":"","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115636296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
SimRank is an influential link-based similarity measure that has been used in many fields of Web search and sociometry. The best-of-breed method by Kusumoto et. al., however, does not always deliver high-quality results, since it fails to accurately obtain its diagonal correction matrix D. Besides, SimRank is also limited by an unwanted "connectivity trait": increasing the number of paths between nodes a and b often incurs a decrease in score s(a,b). The best-known solution, SimRank++, cannot resolve this problem, since a revised score will be zero if a and b have no common in-neighbors. In this paper, we consider high-quality similarity search. Our scheme, SR#, is efficient and semantically meaningful: (1) We first formulate the exact D, and devise a "varied-D" method to accurately compute SimRank in linear memory. Moreover, by grouping computation, we also reduce the time of from quadratic to linear in the number of iterations. (2) We design a "kernel-based" model to improve the quality of SimRank, and circumvent the "connectivity trait" issue. (3) We give mathematical insights to the semantic difference between SimRank and its variant, and correct an argument: "if D is replaced by a scaled identity matrix, top-K rankings will not be affected much". The experiments confirm that SR# can accurately extract high-quality scores, and is much faster than the state-of-the-art competitors.
{"title":"High Quality Graph-Based Similarity Search","authors":"Weiren Yu, J. Mccann","doi":"10.1145/2766462.2767720","DOIUrl":"https://doi.org/10.1145/2766462.2767720","url":null,"abstract":"SimRank is an influential link-based similarity measure that has been used in many fields of Web search and sociometry. The best-of-breed method by Kusumoto et. al., however, does not always deliver high-quality results, since it fails to accurately obtain its diagonal correction matrix D. Besides, SimRank is also limited by an unwanted \"connectivity trait\": increasing the number of paths between nodes a and b often incurs a decrease in score s(a,b). The best-known solution, SimRank++, cannot resolve this problem, since a revised score will be zero if a and b have no common in-neighbors. In this paper, we consider high-quality similarity search. Our scheme, SR#, is efficient and semantically meaningful: (1) We first formulate the exact D, and devise a \"varied-D\" method to accurately compute SimRank in linear memory. Moreover, by grouping computation, we also reduce the time of from quadratic to linear in the number of iterations. (2) We design a \"kernel-based\" model to improve the quality of SimRank, and circumvent the \"connectivity trait\" issue. (3) We give mathematical insights to the semantic difference between SimRank and its variant, and correct an argument: \"if D is replaced by a scaled identity matrix, top-K rankings will not be affected much\". The experiments confirm that SR# can accurately extract high-quality scores, and is much faster than the state-of-the-art competitors.","PeriodicalId":297035,"journal":{"name":"Proceedings of the 38th International ACM SIGIR Conference on Research and Development in Information Retrieval","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115736601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}