{"title":"Self-Supervised Bot Play for Transcript-Free Conversational Critiquing with Rationales","authors":"Shuyang Li, Bodhisattwa Prasad Majumder, Julian McAuley","doi":"10.1145/3665502","DOIUrl":"https://doi.org/10.1145/3665502","url":null,"abstract":"\u0000 Conversational critiquing in recommender systems offers a way for users to engage in multi-turn conversations to find items they enjoy. For users to trust an agent and give effective feedback, the recommender system must be able to\u0000 explain\u0000 its suggestions and rationales. We develop a two-part framework for training multi-turn conversational critiquing in recommender systems that provide recommendation rationales that users can effectively interact with to receive better recommendations. First, we train a recommender system to jointly suggest items and explain its reasoning via subjective rationales. We then fine-tune this model to incorporate iterative user feedback via self-supervised bot-play. Experiments on three real-world datasets demonstrate that our system can be applied to different recommendation models across diverse domains to achieve state-of-the-art performance in multi-turn recommendation. Human studies show that systems trained with our framework provide more useful, helpful, and knowledgeable suggestions in warm- and cold-start settings. Our framework allows us to use only product reviews during training, avoiding the need for expensive dialog transcript datasets that limit the applicability of previous conversational recommender agents.\u0000","PeriodicalId":474833,"journal":{"name":"ACM Transactions on Recommender Systems","volume":"4 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141118752","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}
Jielin Jiang, Pengcheng Guo, Xiaolong Xu, Jintao Wu, Yan Cui
{"title":"Social Perception with Graph Attention Network for Recommendation","authors":"Jielin Jiang, Pengcheng Guo, Xiaolong Xu, Jintao Wu, Yan Cui","doi":"10.1145/3665503","DOIUrl":"https://doi.org/10.1145/3665503","url":null,"abstract":"\u0000 Recommendation systems are designed to uncover users’ potential preferences and make recommendations. However, they often face challenges such as data sparsity and the cold start problem. Although the introduction of knowledge graphs has partially addressed the issue of data sparsity, the challenge of cold start has not been effectively resolved. In this paper, a novel approach called\u0000 Social Perception with Graph Attention Network (SPGAT)\u0000 for Recommendation is proposed. In SPGAT, we aim to leverage social perception to solve the cold start effectively for more accurate recommendations. The approach utilizes a multi-layer graph attention network to aggregate user preference features from collaborative knowledge graphs and social perception graphs. By analyzing the social network of a new user, associated friend users can be identified. The interaction data of these friend users is then provided as side information to recommend to the new user. To handle one-to-many and many-to-many relations, we introduce the TransD graph embedding model, which maps different types of relations and entities to different spaces. To optimize the proposed SPGAT, self-adversarial negative sampling is utilized to implement entity and relation embedding and generate negative samples. Experimental results demonstrate that SPGAT has achieved superior performance compared to several advanced methods.\u0000","PeriodicalId":474833,"journal":{"name":"ACM Transactions on Recommender Systems","volume":"28 49","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141118259","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}
Christine Bauer, Chandni Bagchi, Olusanmi A. Hundogan, Karin van Es
{"title":"Where are the Values? A Systematic Literature Review on News Recommender Systems","authors":"Christine Bauer, Chandni Bagchi, Olusanmi A. Hundogan, Karin van Es","doi":"10.1145/3654805","DOIUrl":"https://doi.org/10.1145/3654805","url":null,"abstract":"In the recommender systems field, it is increasingly recognized that focusing on accuracy measures is limiting and misguided. Unsurprisingly, in recent years, the field has witnessed more interest in the research of values “beyond accuracy.” This trend is particularly pronounced in the news domain where recommender systems perform parts of the editorial function, required to uphold journalistic values of news organizations. In the literature, various values and approaches have been proposed and evaluated. This paper reviews the current state of the proposed news recommender systems (NRS). We perform a systematic literature review, analyzing 183 papers. The primary aim is to study the development, scope, and focus of value-aware NRS over time. In contrast to previous surveys, we are particularly interested in identifying the range of values discussed and evaluated in the context of NRS, and embrace an interdisciplinary view. We identified a total of 40 values, categorized into five value groups. Most research on value-aware NRS has taken an algorithmic approach, whereas conceptual discussions are comparably scarce. Often, algorithms are evaluated by accuracy-based metrics, but the values are not evaluated with respective measures. Overall, our work identifies research gaps concerning values that have not received much attention. Values need to be targeted on a more fine-grained and specific level.","PeriodicalId":474833,"journal":{"name":"ACM Transactions on Recommender Systems","volume":"91 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140370871","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":"Unbiased, Effective, and Efficient Distillation from Heterogeneous Models for Recommender Systems","authors":"SeongKu Kang, Wonbin Kweon, Dongha Lee, Jianxun Lian, Xing Xie, Hwanjo Yu","doi":"10.1145/3649443","DOIUrl":"https://doi.org/10.1145/3649443","url":null,"abstract":"In recent years, recommender systems have achieved remarkable performance by using ensembles of heterogeneous models. However, this approach is costly due to the resources and inference latency proportional to the number of models, creating a bottleneck for production. Our work aims to transfer the ensemble knowledge of heterogeneous teachers to a lightweight student model using knowledge distillation (KD), reducing inference costs while maintaining high accuracy. We find that the efficacy of distillation decreases when transferring knowledge from heterogeneous teachers. To address this, we propose a new KD framework, named HetComp, that guides the student model by transferring easy-to-hard sequences of knowledge generated from teachers’ trajectories. HetComp uses dynamic knowledge construction to provide progressively difficult ranking knowledge and adaptive knowledge transfer to gradually transfer finer-grained ranking information. Although HetComp improves accuracy, it exacerbates popularity bias, resulting in a high popularity lift. To mitigate this issue, we introduce two strategies that leverage models’ disagreement knowledge (i.e., dissensus) for heterogeneous comparison. Our experiments demonstrate that HetComp significantly enhances distillation quality and the student model’s generalization capabilities. Furthermore, we provide extensive experimental results supporting the effectiveness of our dissensus-based debiasing techniques in mitigating the popularity lift caused by HetComp.","PeriodicalId":474833,"journal":{"name":"ACM Transactions on Recommender Systems","volume":"30 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139957314","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":"Ranking the causal impact of recommendations under collider bias in\u0000 k\u0000 -spots recommender systems","authors":"Aleix Ruiz de Villa, Gabriele Sottocornola, Ludovik Çoba, Federico Lucchesi, Bartłomiej Skorulski","doi":"10.1145/3643139","DOIUrl":"https://doi.org/10.1145/3643139","url":null,"abstract":"\u0000 The first objective of recommender systems is to provide personalized recommendations for each user. However, personalization may not be its only use. Past recommendations can be further analyzed to gain global insights into users’ behavior with respect to recommended items. Such insights can help to answer design-related questions such as which items’ recommendations are the most impactful in terms of users’ utility, which type of recommendations are the most followed ones, which items could be dropped from the catalog, or which recommendations are under-performing compared to what one would expect. In order to answer those questions, we need to rank item recommendations’ performances in terms of their causal impact on some user-related outcome measures. Unfortunately, in previous work leveraging causal inference for recommendation systems, the attention is fully focused on correcting confounding bias and not on the collider bias. This bias is particularly relevant in the recommender context, where multiple items are simultaneously recommended. Indeed, when there is a fixed number of available spots (i.e.,\u0000 k\u0000 -spots) and recommendations need to be provided at each session, we argue that it is not possible to estimate the causal impacts of recommendations but only the differences between them. Therefore, in this paper, we provide an unbiased estimator of the differences in the impacts of items’ recommendations, that work for any outcome of interest, and any type of recommender system as long as it has some degree of randomization. We apply our results both in a simulated environment and in a real-world offline environment leveraging logged data for recommended items in a digital healthcare app.\u0000","PeriodicalId":474833,"journal":{"name":"ACM Transactions on Recommender Systems","volume":"22 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140478053","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}