{"title":"“You Really Get Me”: Conversational AI Agents That Can Truly Understand and Help Users","authors":"Michelle X. Zhou","doi":"10.1145/3383313.3418436","DOIUrl":"https://doi.org/10.1145/3383313.3418436","url":null,"abstract":"Have you watched the movie Her? Have you ever wondered or wished to have an AI companion like Samantha, who could tell you what you really are, whom your best teammate may be, and which career path would be best for you? In this talk, Michelle will present a framework for building hyper-personalized, conversational Artificial Intelligent (AI) agents who can deeply understand users and responsibly guide user behavior in both virtual and real world. Through live demos, she will highlight two technical advances of the framework: (1) evidence-based personality inference and (2) model-based conversation generation. Michelle will discuss real-world applications of these agents and the wider implications of enabling hyper-personalized conversational AI agents for businesses and individuals.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":" 16","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120829464","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":"Content-Collaborative Disentanglement Representation Learning for Enhanced Recommendation","authors":"Yin Zhang, Ziwei Zhu, Yun He, James Caverlee","doi":"10.1145/3383313.3412239","DOIUrl":"https://doi.org/10.1145/3383313.3412239","url":null,"abstract":"Modern recommenders usually consider both collaborative features from user behavior data (e.g., clicks) and content information about the users and items (e.g., user ages or item images) for improved recommendations. While encouraging, the uncovered user preference representations derived from these collaborative and content-based perspectives can be entangled by intermixing the influence from each other, leading to sub-optimal performance and unstable recommendations. Hence, we propose to disentangle representations learned from user behavior data and content information. Specifically, we propose a novel two-level disentanglement generative recommendation model (DICER) that supports both content-collaborative disentanglement and feature disentanglement: for the content-collaborative disentanglement, DICER decomposes the features by their marginal distributions based on content and user-item interactions, to ensure the learned features from each type are statistically independent. For feature disentanglement, by decomposing the Kullback-Leibler divergence, we theoretically show that extracted features within each type are disentangled at a granular level. Furthermore, DICER utilizes a co-decoder that simultaneously decodes the content and user-item interactions to ensure the high-quality of learned features. Through extensive experiments on three real-world datasets, results show that DICER significantly outperforms other state-of-the-art methods by 13.5% in NDCG and 14.4% in hit ratio on average.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127235925","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}
P. Symeonidis, Andrea Janes, Dmitry Chaltsev, Philip Giuliani, Daniel Morandini, A. Unterhuber, Ludovik Çoba, M. Zanker
{"title":"Recommending the Video to Watch Next: An Offline and Online Evaluation at YOUTV.de","authors":"P. Symeonidis, Andrea Janes, Dmitry Chaltsev, Philip Giuliani, Daniel Morandini, A. Unterhuber, Ludovik Çoba, M. Zanker","doi":"10.1145/3383313.3412257","DOIUrl":"https://doi.org/10.1145/3383313.3412257","url":null,"abstract":"The task “recommend a video to watch next?” has been in the focus of recommender systems’ research for a long time. However, adequately exploiting the clues hidden in the sequences of actions of user sessions in order to reveal users’ short-term intentions moved only recently into the focus of research. Based on a real-world application scenario, in this paper, we propose a Markov Chain-based transition probability matrix to efficiently reveal the short-term preferences of individuals. We experimentally evaluated our proposed method by comparing it against state-of-the-art algorithms in an offline as well as a live evaluation setting. In both cases our method not only demonstrated its superiority over its competitors, but exposed a clearly stronger engagement of users on the platform. In the online setting, our method improved the click-through rate by up to 93.61%. This paper therefore contributes real-world evidence for improving the recommendation effectiveness, by considering sequence-awareness, since capturing the short-term preferences of users is crucial in the light of items with a short life span such as tv programs (news, tv shows, etc.).","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115990208","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":"Closed-Form Models for Collaborative Filtering with Side-Information","authors":"Olivier Jeunen, J. V. Balen, Bart Goethals","doi":"10.1145/3383313.3418480","DOIUrl":"https://doi.org/10.1145/3383313.3418480","url":null,"abstract":"Recent work has shown that, despite their simplicity, item-based models optimised through ridge regression can attain highly competitive results on collaborative filtering tasks. As these models are analytically computable and thus forgo the need for often expensive iterative optimisation procedures, they are an attractive choice for practitioners. We study the applicability of such closed-form models to implicit-feedback collaborative filtering when additional side-information or metadata about items is available. Two complementary extensions to the easer paradigm are proposed, based on collective and additive models. Through an extensive empirical analysis on several large-scale datasets, we show that our methods can effectively exploit side-information whilst retaining a closed-form solution, and improve upon the state-of-the-art without increasing the computational complexity of the original easer approach. Additionally, empirical results demonstrate that the use of side-information leads to more “long tail” items being recommended, benefiting the recommendations’ coverage of the item catalogue.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122643156","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":"Conversational Agents for Recommender Systems","authors":"Andrea Iovine","doi":"10.1145/3383313.3411453","DOIUrl":"https://doi.org/10.1145/3383313.3411453","url":null,"abstract":"In my Ph.D. work, my objective is to improve the state of the art in Conversational Recommender Systems, by proposing a model that closely follows the process that people enact when searching for products and services. Rich user profiles are elicited using natural language dialogue. Item descriptions will be extracted from a combination of structured and unstructured data such as user reviews. Natural language explanations will ensure that users can quickly understand the reasoning behind the recommendations. Interactive explanation will then allow them to further compare several alternatives. This extended abstract presents the motivations of my work, it details the research plan, and the research questions. Finally, it shows some preliminary results, and outlines the next steps for my Ph.D. program.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"397 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124696502","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":"A Ranking Optimization Approach to Latent Linear Critiquing for Conversational Recommender Systems","authors":"Hanze Li, S. Sanner, Kai Luo, Ga Wu","doi":"10.1145/3383313.3412240","DOIUrl":"https://doi.org/10.1145/3383313.3412240","url":null,"abstract":"Critiquing is a method for conversational recommendation that incrementally adapts recommendations in response to user preference feedback. Specifically, a user is iteratively provided with item recommendations and attribute descriptions for those items; the user may then either accept the recommendation or choose to critique an attribute to generate a new recommendation. A recent direction known as latent linear critiquing (LLC) takes a modern embedding-based approach that seeks to optimize the combination of user preference embeddings with embeddings of critiques based on subjective item descriptions (i.e., keyphrases from user reviews); LLC does so by exploiting the linear structure of the embeddings to efficiently optimize their weights in a linear programming (LP) formulation. In this paper, we revisit LLC and note that it’s score-based optimization approach inherently encourages extreme weightings in order to maximize predicted score gaps between preferred and non-preferred items. Noting that the overall end task objective in critiquing is to re-rank rather than re-score, in this paper we take a ranking optimization approach that seeks to optimize embedding weights based on observed rank violations from earlier critiquing iterations. We evaluate the proposed framework on two recommendation datasets containing user reviews. Empirical results demonstrate that ranking-based LLC generally outperforms scoring-based LLC and other baselines across a variety of datasets, critiquing styles, and both satisfaction and session-length performance metrics.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124313896","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":"Workshop on Online Misinformation- and Harm-Aware Recommender Systems","authors":"Antonela Tommasel, D. Godoy, A. Zubiaga","doi":"10.1145/3383313.3411537","DOIUrl":"https://doi.org/10.1145/3383313.3411537","url":null,"abstract":"Recommender systems play an important role in the dissemination and propagation of information. This is particularly true for large scale platforms such as social media, where recommender systems assist users in facilitating access to massive user-generated content by finding relevant information and establishing new social relationships. Just as recommendation techniques are designed to become powerful tools, they could in turn spread online harm. Some of these issues stem from the core concepts and assumptions of recommender systems. Harnessing recommender systems with misinformation- and harm-awareness mechanisms becomes essential not only to mitigate the negative effects of the propagation of harmful content, but also to increase the quality and diversity of recommender systems. To further research in this direction, the Workshop on Online Misinformation- and Harm-Aware Recommender Systems (OHARS 2020) aimed at fostering research in recommender systems that can circumvent the negative effects of online harms by promoting the recommendation of safe content and users.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126331279","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":"Doubly Robust Estimator for Ranking Metrics with Post-Click Conversions","authors":"Yuta Saito","doi":"10.1145/3383313.3412262","DOIUrl":"https://doi.org/10.1145/3383313.3412262","url":null,"abstract":"Post-click conversion, a pre-defined action on a web service after a click, is an essential form of feedback, as it directly contributes to the final revenue and accurately captures user preferences for items, compared with the ambiguous click. However, naively using post-click conversions can lead to severe bias when learning or evaluating recommenders because of the selection bias between clicked and unclicked data. In this study, we address the offline evaluation problem of algorithmic recommendations with biased post-click conversions. A possible solution to address this bias is to use the inverse propensity score estimator, as it can provide an unbiased evaluation even with the selection bias. However, this estimator is known to be subject to variance and instability problems, which can be severe in the recommendation setting, as feedback is often highly sparse. To address these limitations with the previous unbiased estimator, we propose a doubly robust estimator for the ground-truth ranking performance of a given recommender. The proposed estimator is unbiased against the ground-truth ranking metric and improves the variance and estimation error tail bound of the existing unbiased estimator. Finally, to evaluate the empirical efficacy of the proposed estimator, we conduct empirical evaluations using semi-synthetic and two public real-world datasets. The results show that the proposed metric reveals a better model evaluation performance compared with existing baseline metrics, particularly in a situation with severe selection bias.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132511477","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":"Adaptive Pointwise-Pairwise Learning-to-Rank for Content-based Personalized Recommendation","authors":"Yagmur Gizem Cinar, J. Renders","doi":"10.1145/3383313.3412229","DOIUrl":"https://doi.org/10.1145/3383313.3412229","url":null,"abstract":"This paper extends the standard pointwise and pairwise paradigms for learning-to-rank in the context of personalized recommendation, by considering these two approaches as two extremes of a continuum of possible strategies. It basically consists of a surrogate loss that models how to select and combine these two approaches adaptively, depending on the context (query or user, pair of items, etc.). In other words, given a training instance, which is typically a triplet (a query/user and two items with different preferences or relevance grades), the strategy adaptively determines whether it is better to focus on the “most preferred” item (pointwise - positive instance), on the “less preferred” one (pointwise - negative instance) or on the pair (pairwise), or on anything else in between these 3 extreme alternatives. We formulate this adaptive strategy as minimizing a particular loss function that generalizes simultaneously the traditional pointwise and pairwise loss functions (negative log-likelihood) through a mixture coefficient. This coefficient is formulated as a learnable function of the features associated to the triplet. Experimental results on several real-world news recommendation datasets show clear improvements over several pointwise, pairwise, and listwise approaches.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128419175","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":"Debiasing Item-to-Item Recommendations With Small Annotated Datasets","authors":"Tobias Schnabel, Paul N. Bennett","doi":"10.1145/3383313.3412265","DOIUrl":"https://doi.org/10.1145/3383313.3412265","url":null,"abstract":"Item-to-item recommendation (e.g., “People who like this also like...”) is a ubiquitous and important type of recommendation in real-world systems. Observational data from historical interaction logs abound in these settings. However, since virtually all observational data exhibit biases, such as time-in-inventory or interface biases, it is crucial that recommender algorithms account for these biases. In this paper, we develop a principled approach for item-to-item recommendation based on causal inference and present a practical and highly effective method for estimating the causal parameters from a small annotated dataset. Empirically, we find that our approach substantially improves upon existing methods while requiring only small amounts of annotated data.","PeriodicalId":310522,"journal":{"name":"Proceedings of the 14th ACM Conference on Recommender Systems","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128528311","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}