OpenRaiser/Intern-Atlas huggingface dataset:
Multileave Gradient Descent for Fast Online Learning to Rank
Authors: Anne Schuth, Harrie Oosterhuis, Shimon Whiteson, Maarten de Rijke
Venue: WSDM
Year: 2016

Modern search systems are based on dozens or even hundreds of ranking features. The dueling bandit gradient descent (DBGD) algorithm has been shown to effectively learn combinations of these features solely from user interactions. DBGD explores the search space by comparing a possibly improved ranker to the current production ranker. To this end, it uses interleaved comparison methods, which can infer with high sensitivity a preference between two rankings based only on interaction data. A limiting factor is that it can compare only to a single exploratory ranker. We propose an online learning to rank algorithm called multileave gradient descent (MGD) that extends DBGD to learn from so-called multileaved comparison methods that can compare a set of rankings instead of merely a pair. We show experimentally that MGD allows for better selection of candidates than DBGD without the need for more comparisons involving users. An important implication of our results is that orders of magnitude less user interaction data is required to find good rankers when multileaved comparisons are used within online learning to rank. Hence, fewer users need to be exposed to possibly inferior rankers and our method allows search engines to adapt more quickly to changes in user preferences.
Optimizing Search Interactions within Professional Social Networks
Authors: Nikita V. Spirin
Venue: WSDM
Year: 2016

To help users cope with the scale and influx of new information, professional social networks (PSNs) provide a search functionality. However, most of the search engines within PSNs today only support keyword queries and basic faceted search capabilities overlooking serendipitous network exploration and search for relationships between entities. This results in siloed information and a limited search space. My thesis is that we must redesign all major elements of a search user interface, such as input, control, and informational, to enable more effective search interactions within PSNs. I will introduce new insights and algorithms supporting the thesis.
Querying and Tracking Influencers in Social Streams
Authors: Karthik Subbian, Charu C. Aggarwal, Jaideep Srivastava
Venue: WSDM
Year: 2016

Influence analysis is an important problem in social network analysis due to its impact on viral marketing and targeted advertisements. Most of the existing influence analysis methods determine the influencers in a static network with an influence propagation model based on pre-defined edge propagation probabilities. However, none of these models can be queried to find influencers in both context and time-sensitive fashion from a streaming social data. In this paper, we propose an approach to maintain real-time influence scores of users in a social stream using a topic and time-sensitive approach, while the network and topic is constantly evolving over time. We show that our approach is efficient in terms of online maintenance and effective in terms various types of real-time context- and time-sensitive queries. We evaluate our results on both social and collaborative network data sets.
Inferring Latent Triggers of Purchases with Consideration of Social Effects and Media Advertisements
Authors: Yusuke Tanaka, Takeshi Kurashima, Yasuhiro Fujiwara, Tomoharu Iwata, Hiroshi Sawada
Venue: WSDM
Year: 2016

This paper proposes a method for inferring from single-source data the factors that trigger purchases. Here, single-source data are the histories of item purchases and media advertisement views for each individual. We assume a sequence of purchase events to be a stochastic process incorporating the following three factors: (a) user preference, (b) social effects received from other users, and (c) media advertising effects. As our user-purchase model incorporates the latent relationships between users and advertisers, it can infer the latent triggers of purchases. Experiments on real single-source data show that our model can (a) achieve high prediction accuracy for purchases, (b) discover the key information, i.e., popular items, influential users, and influential advertisers, (c) estimate the relative impact of the three factors on purchases, and (d) find user segments according to the estimated factors.
Mining Complaints to Improve a Product: a Study about Problem Phrase Extraction from User Reviews
Authors: Elena Tutubalina
Venue: WSDM
Year: 2016

The rapidly growing availability of user reviews has become an important resource for companies to detect customer dissatisfaction from textual opinions. Much research in opinion mining focuses on extracting customers' opinions from products' reviews and predicting their sentiment orientation or ratings with the aim of helping other users to make a decision on whether to buy a product. However, there have been few recent studies conducted on business-related opinion tasks to extract more refined opinions about a product's quality problems or technical failures. The focus of this study is the extraction of problem phrases, mentioned in user reviews about products. We explore main opinion mining tasks to determine whether given text from reviews contains a mention of a problem. We formulate research questions and propose knowledge-based methods and probabilistic models to classify users' phrases and extract latent problem indicators, aspects and related sentiments from online reviews.
Term-by-Term Query Auto-Completion for Mobile Search
Authors: Saúl Vargas, Roi Blanco, Peter Mika
Venue: WSDM
Year: 2016

With the ever increasing usage of mobile search, where text input is typically slow and error-prone, assisting users to formulate their queries contributes to a more satisfactory search experience. Query auto-completion (QAC) techniques, which predict possible completions for user queries, are the archetypal example of query assistance and are present in most search engines. We argue, however, that classic QAC, which operates by suggesting whole-query completions, may be sub-optimal for the case of mobile search as the available screen real estate to show suggestions is limited and editing is typically slower than in desktop search. In this paper we propose the idea of term-by-term QAC, which is a new technique inspired by predictive keyboards that suggests to the user one term at a time, instead of whole-query completions. We describe an efficient mechanism to implement this technique and an adaptation of a prior user model to evaluate the effectiveness of both standard and term-by-term QAC approaches using query log data. Our experiments with a mobile query log from a commercial search engine show the validity of our approach according to this user model with respect to saved characters, saved terms and examination effort. Finally, a user study provides further insights about our term-by-term technique compared with standard QAC with respect to the variables analyzed in the query log-based evaluation and additional variables related to the successfulness, the speed of the interactions and the properties of the submitted queries.
WSDM Cup 2016: Entity Ranking Challenge
Authors: Alex D. Wade, Kuansan Wang, Yizhou Sun, Antonio Gulli
Venue: WSDM
Year: 2016

In this paper, we describe the WSDM Cup entity ranking challenge held in conjunction with the 2016 Web Search and Data Mining conference (WSDM 2016). Participants in the challenge were provided access to the Microsoft Academic Graph (MAG), a large heterogeneous graph of academic entities, and were invited to calculate the query-independent importance of each publication in the graph. Submissions for the challenge were open from August through November 2015, and a public leaderboard displayed teams? progress against a set of training judgements. Final evaluations were performed against a separate, withheld portion of the evaluation judgements. The top eight performing teams were then invited to submit papers to the WSDM Cup workshop, held at the WSDM 2016 conference.
Modeling Check-in Preferences with Multidimensional Knowledge: A Minimax Entropy Approach
Authors: Jingjing Wang, Min Li, Jiawei Han, Xiaolong Wang
Venue: WSDM
Year: 2016

We propose a single unified minimax entropy approach for user preference modeling with multidimensional knowledge. Our approach provides a discriminative learning protocol which is able to simultaneously a) leverage explicit human knowledge, which are encoded as explicit features, and b) model the more ambiguous hidden intent, which are encoded as latent features. A latent feature can be carved by any parametric form, which allows it to accommodate arbitrary underlying assumptions. We present our approach in the scenario of check-in preference learning and demonstrate it is capable of modeling user preference in an optimized manner.
Beyond Ranking: Optimizing Whole-Page Presentation
Authors: Yue Wang, Dawei Yin, Luo Jie, Pengyuan Wang, Makoto Yamada, Yi Chang, Qiaozhu Mei
Venue: WSDM
Year: 2016

Modern search engines aggregate results from different verticals: webpages, news, images, video, shopping, knowledge cards, local maps, etc. Unlike "ten blue links", these search results are heterogeneous in nature and not even arranged in a list on the page. This revolution directly challenges the conventional "ranked list" formulation in ad hoc search. Therefore, finding proper presentation for a gallery of heterogeneous results is critical for modern search engines.
Hierarchical Label Propagation and Discovery for Machine Generated Email
Authors: James B. Wendt, Michael Bendersky, Lluis Garcia Pueyo, Vanja Josifovski, Balint Miklos, Ivo Krka, Amitabh Saikia, Jie Yang, Marc-Allen Cartright, Sujith Ravi
Venue: WSDM
Year: 2016

Machine-generated documents such as email or dynamic web pages are single instantiations of a pre-defined structural template. As such, they can be viewed as a hierarchy of template and document specific content. This hierarchical template representation has several important advantages for document clustering and classification. First, templates capture common topics among the documents, while filtering out the potentially noisy variabilities such as personal information. Second, template representations scale far better than document representations since a single template captures numerous documents. Finally, since templates group together structurally similar documents, they can propagate properties between all the documents that match the template. In this paper, we use these advantages for document classification by formulating an efficient and effective hierarchical label propagation and discovery algorithm. The labels are propagated first over a template graph (constructed based on either term-based or topic-based similarities), and then to the matching documents. We evaluate the performance of the proposed algorithm using a large donated email corpus and show that the resulting template graph is significantly more compact than the corresponding document graph and the hierarchical label propagation is both efficient and effective in increasing the coverage of the baseline document classification algorithm. We demonstrate that the template label propagation achieves more than 91% precision and 93% recall, while increasing the label coverage by more than 11%.
Relational Learning with Social Status Analysis
Authors: Liang Wu, Xia Hu, Huan Liu
Venue: WSDM
Year: 2016

Relational learning has been proposed to cope with the interdependency among linked instances in social network analysis, which often adopts network connectivity and social media content for prediction. A common assumption in existing relational learning methods is that data instances are equally important. The algorithms developed based on the assumption may be significantly affected by outlier data and thus less robust. In the meantime, it has been well established in social sciences that actors are naturally of different social status in a social network. Motivated by findings from social sciences, in this paper, we investigate whether social status analysis could facilitate relational learning. Particularly, we propose a novel framework RESA to model social status using the network structure. It extracts robust and intrinsic latent social dimensions for social actors, which are further exploited as features for supervised learning models. The proposed method is applicable for real-world relational learning problems where noise exists. Extensive experiments are conducted on datasets obtained from real-world social media platforms. Empirical results demonstrate the effectiveness of RESA and further experiments are conducted to help understand the effects of parameter settings to the proposed model and how local social status works.
Nonlinear Laplacian for Digraphs and its Applications to Network Analysis
Authors: Yuichi Yoshida
Venue: WSDM
Year: 2016

In this work, we introduce a new Markov operator associated with a digraph, which we refer to as a nonlinear Laplacian. Unlike previous Laplacians for digraphs, the nonlinear Laplacian does not rely on the stationary distribution of the random walk process and is well defined on digraphs that are not strongly connected. We show that the nonlinear Laplacian has nontrivial eigenvalues and give a Cheeger-like inequality, which relates the conductance of a digraph and the smallest non-zero eigenvalue of its nonlinear Laplacian. Finally, we apply the nonlinear Laplacian to the analysis of real-world networks and obtain encouraging results.
Geographic Segmentation via Latent Poisson Factor Model
Authors: Rose Yu, Andrew Gelfand, Suju Rajan, Cyrus Shahabi, Yan Liu
Venue: WSDM
Year: 2016

Discovering latent structures in spatial data is of critical importance to understanding the user behavior of location-based services. In this paper, we study the problem of geographic segmentation of spatial data, which involves dividing a collection of observations into distinct geo-spatial regions and uncovering abstract correlation structures in the data. We introduce a novel, Latent Poisson Factor (LPF) model to describe spatial count data. The model describes the spatial counts as a Poisson distribution with a mean that factors over a joint item-location latent space. The latent factors are constrained with weak labels to help uncover interesting spatial dependencies. We study the LPF model on a mobile app usage data set and a news article readership data set. We empirically demonstrate its effectiveness on a variety of prediction tasks on these two data sets.
Learning Distributed Representations of Data in Community Question Answering for Question Retrieval
Authors: Kai Zhang, Wei Wu, Fang Wang, Ming Zhou, Zhoujun Li
Venue: WSDM
Year: 2016

We study the problem of question retrieval in community question answering (CQA). The biggest challenge within this task is lexical gaps between questions since similar questions are usually expressed with different but semantically related words. To bridge the gaps, state-of-the-art methods incorporate extra information such as word-to-word translation and categories of questions into the traditional language models. We find that the existing language model based methods can be interpreted using a new framework, that is they represent words and question categories in a vector space and calculate question-question similarities with a linear combination of dot products of the vectors. The problem is that these methods are either heuristic on data representation or difficult to scale up. We propose a principled and efficient approach to learning representations of data in CQA. In our method, we simultaneously learn vectors of words and vectors of question categories by optimizing an objective function naturally derived from the framework. In question retrieval, we incorporate learnt representations into traditional language models in an effective and efficient way. We conduct experiments on large scale data from Yahoo! Answers and Baidu Knows, and compared our method with state-of-the-art methods on two public data sets. Experimental results show that our method can significantly improve on baseline methods for retrieval relevance. On 1 million training data, our method takes less than 50 minutes to learn a model on a single multicore machine, while the translation based language model needs more than 2 days to learn a translation table on the same machine.
E-commerce Product Recommendation by Personalized Promotion and Total Surplus Maximization
Authors: Qi Zhao
Venue: WSDM
Year: 2016

Existing recommendation algorithms treat recommendation problem as rating prediction and the recommendation quality is measured by RMSE or other similar metrics. However, we argued that when it comes to E-commerce product recommendation, recommendation is more than rating prediction by realizing the fact price plays a critical role in recommendation result. In this work, we propose to build E-commerce product recommender systems based on fundamental economic notions. We first proposed an incentive compatible method that can effectively elicit consumer's willingness-to-pay in a typical E-commerce setting and in a further step, we formalize the recommendation problem as maximizing total surplus. We validated the proposed WTP elicitation algorithm through crowd sourcing and the results demonstrated that the proposed approach can achieve higher seller profit by personalizing promotion. We also proposed a total surplus maximization (TSM) based recommendation framework. We specified TSM by three of the most representative settings - e-commerce where the product quantity can be viewed as infinity, P2P lending where the resource is bounded and freelancer marketing where the resource (job) can be assigned to one freelancer. The experimental results of the corresponding datasets shows that TSM exceeds existing approach in terms of total surplus.
Leveraging Behavioral Factorization and Prior Knowledge for Community Discovery and Profiling
Authors: Mohammad Akbari, Tat-Seng Chua
Venue: WSDM
Year: 2017

Recently community detection has attracted much interest in social media to understand the collective behaviours of users and allow individuals to be modeled in the context of the group. Most existing approaches for community detection exploit either users' social links or their published content, aiming at discovering groups of densely connected or highly similar users. They often fail to find effective communities due to excessive noise in content, sparsity in links, and heterogenous behaviours of users in social media. Further, they are unable to provide insights and rationales behind the formation of the group and the collective behaviours of the users. To tackle these challenges, we propose to discover communities in a low- dimensional latent space in which we simultaneously learn the representation of users and communities. In particular, we integrated different social views of the network into a low-dimensional latent space in which we sought dense clusters of users as communities. By imposing a Laplacian regularizer into affiliation matrix, we further incorporated prior knowledge into the community discovery process. Finally community profiles were computed by a linear operator integrating the profiles of members. Taking the wellness domain as an example, we conducted experiments on a large scale real world dataset of users tweeting about diabetes and its related concepts, which demonstrate the effectiveness of our approach in discovering and profiling user communities.
Online Actions with Offline Impact: How Online Social Networks Influence Online and Offline User Behavior
Authors: Tim Althoff, Pranav Jindal, Jure Leskovec
Venue: WSDM
Year: 2017

Many of today's most widely used computing applications utilize social networking features and allow users to connect, follow each other, share content, and comment on others' posts. However, despite the widespread adoption of these features, there is little understanding of the consequences that social networking has on user retention, engagement, and online as well as offline behavior. Here, we study how social networks influence user behavior in a physical activity tracking application. We analyze 791 million online and offline actions of 6 million users over the course of 5 years, and show that social networking leads to a significant increase in users' online as well as offline activities. Specifically, we establish a causal effect of how social networks influence user behavior. We show that the creation of new social connections increases user online in-application activity by 30%, user retention by 17%, and user offline real-world physical activity by 7% (about 400 steps per day). By exploiting a natural experiment we distinguish the effect of social influence of new social connections from the simultaneous increase in user's motivation to use the app and take more steps. We show that social influence accounts for 55% of the observed changes in user behavior, while the remaining 45% can be explained by the user's increased motivation to use the app. Further, we show that subsequent, individual edge formations in the social network lead to significant increases in daily steps. These effects diminish with each additional edge and vary based on edge attributes and user demographics. Finally, we utilize these insights to develop a model that accurately predicts which users will be most influenced by the creation of new social network connections.
Ten Years of Wisdom
Authors: Ricardo Baeza-Yates
Venue: WSDM
Year: 2017

In this keynote we attempt to cover the first ten years of ACM WSDM, the main conference on web search and data mining. We start from its inception during 2006 to the first conference held at Stanford in 2008, driven by some key people in the main web search engines of that time. We were confident on its success, but we never expected to become so fast the best venue for our research topics. We also cover the main highlights during all these years as well as current and future trends.
Groove Radio: A Bayesian Hierarchical Model for Personalized Playlist Generation
Authors: Shay Ben-Elazar, Gal Lavee, Noam Koenigstein, Oren Barkan, Hilik Berezin, Ulrich Paquet, Tal Zaccai
Venue: WSDM
Year: 2017

This paper describes an algorithm designed for Microsoft's Groove music service, which serves millions of users world wide. We consider the problem of automatically generating personalized music playlists based on queries containing a ``seed'' artist and the listener's user ID. Playlist generation may be informed by a number of information sources including: user specific listening patterns, domain knowledge encoded in a taxonomy, acoustic features of audio tracks, and overall popularity of tracks and artists. The importance assigned to each of these information sources may vary depending on the specific combination of user and seed~artist.
Algorithms for Active Classifier Selection: Maximizing Recall with Precision Constraints
Authors: Paul N. Bennett, David Maxwell Chickering, Christopher Meek, Xiaojin Zhu
Venue: WSDM
Year: 2017

Software applications often use classification models to trigger specialized experiences for users. Search engines, for example, use query classifiers to trigger specialized "instant answer" experiences where information satisfying the user query is shown directly on the result page, and email applications use classification models to automatically move messages to a spam folder. When such applications have acceptable default (i.e., non-specialized) behavior, users are often more sensitive to failures in model precision than failures in model recall. In this paper, we consider model-selection algorithms for these precision-constrained scenarios. We develop adaptive model-selection algorithms to identify, using as few samples as possible, the best classifier from among a set of (precision) qualifying classifiers. We provide statistical correctness and sample complexity guarantees for our algorithms. We show with an empirical validation that our algorithms work well in practice.