OpenRaiser/Intern-Atlas huggingface dataset:
Comparative Document Analysis for Large Text Corpora
Authors: Xiang Ren, Yuanhua Lv, Kuansan Wang, Jiawei Han
Venue: WSDM
Year: 2017

This paper presents a novel research problem, Comparative Document Analysis (CDA), that is, joint discovery of commonalities and differences between two individual documents (or two sets of documents) in a large text corpus. Given any pair of documents from a (background) document collection, CDA aims to automatically identify sets of quality phrases to summarize the commonalities of both documents and highlight the distinctions of each with respect to the other informatively and concisely. Our solution uses a general graph-based framework to derive novel measures on phrase semantic commonality and pairwise distinction, where the background corpus is used for computing phrase-document semantic relevance. We use the measures to guide the selection of sets of phrases by solving two joint optimization problems. A scalable iterative algorithm is developed to integrate the maximization of phrase commonality or distinction measure with the learning of phrase-document semantic relevance. Experiments on large text corpora from two different domains---scientific papers and news---demonstrate the effectiveness and robustness of the proposed framework on comparing documents. Analysis on a 10GB+ text corpus demonstrates the scalability of our method, whose computation time grows linearly as the corpus size increases. Our case study on comparing news articles published at different dates shows the power of the proposed method on comparing sets of documents.
The Influence of Early Respondents: Information Cascade Effects in Online Event Scheduling
Authors: Daniel M. Romero, Katharina Reinecke, Lionel P. Robert Jr.
Venue: WSDM
Year: 2017

Sequential group decision-making processes, such as online event scheduling, can be subject to social influence if the decisions involve individuals? subjective preferences and values. Indeed, prior work has shown that scheduling polls that allow respondents to see others' answers are more likely to succeed than polls that hide other responses, suggesting the impact of social influence and coordination. In this paper, we investigate whether this difference is due to information cascade effects in which later respondents adopt the decisions of earlier respondents. Analyzing more than 1.3 million Doodle polls, we found evidence that cascading effects take place during event scheduling, and in particular, that early respondents have a larger influence on the outcome of a poll than people who come late. Drawing on simulations of an event scheduling model, we compare possible interventions to mitigate this bias and show that we can optimize the success of polls by hiding the responses of a small percentage of low availability respondents.
Location Influence in Location-based Social Networks
Authors: Muhammad Aamir Saleem, Rohit Kumar, Toon Calders, Xike Xie, Torben Bach Pedersen
Venue: WSDM
Year: 2017

Location-based social networks (LBSN) are social networks complemented with location data such as geo-tagged activity data of its users. In this paper, we study how users of a LBSN are navigating between locations and based on this information we select the most influential locations. In contrast to existing works on influence maximization, we are not per se interested in selecting the users with the largest set of friends or the set of locations visited by the most users; instead, we introduce a notion of location influence that captures the ability of a set of locations to reach out geographically. We provide an exact on-line algorithm and a more memory-efficient but approximate variant based on the HyperLogLog sketch to maintain a data structure called Influence Oracle that allows to efficiently find a top-k set of influential locations. Experiments show that our algorithms are efficient and scalable and that our new location influence notion favors diverse sets of locations with a large geographical spread.
Modeling Event Importance for Ranking Daily News Events
Authors: Vinay Setty, Abhijit Anand, Arunav Mishra, Avishek Anand
Venue: WSDM
Year: 2017

We deal with the problem of ranking news events on a daily basis for large news corpora, an essential building block for news aggregation. News ranking has been addressed in the literature before but with individual news articles as the unit of ranking. However, estimating event importance accurately requires models to quantify current day event importance as well as its significance in the historical context. Consequently, in this paper we show that a cluster of news articles representing an event is a better unit of ranking as it provides an improved estimation of popularity, source diversity and authority cues. In addition, events facilitate quantifying their historical significance by linking them with long-running topics and recent chain of events. Our main contribution in this paper is to provide effective models for improved news event ranking.
New Probabilistic Models for Recommender Systems with Rich Contextual and Content Information
Authors: Eliezer de Souza da Silva
Venue: WSDM
Year: 2017

This project is focused on the design of probabilistic models for recommender systems and collaborative ltering by extending and creating new models to include rich contextual and content information (content, user social network, location, time, user intent, etc), and developing scalable approximate inference algorithms for these models. The working hypothesis is that big data analytics combined with probabilistic modelling, through automatically mining of various data sources and combining di erent latent factors explaining the user interaction with the items, can be used to better infer the user behaviour and generate improved recommendations.
Random Semantic Tensor Ensemble for Scalable Knowledge Graph Link Prediction
Authors: Yi Tay, Anh Tuan Luu, Siu Cheung Hui, Falk Brauer
Venue: WSDM
Year: 2017

Link prediction on knowledge graphs is useful in numerous application areas such as semantic search, question answering, entity disambiguation, enterprise decision support, recommender systems and so on. While many of these applications require a reasonably quick response and may operate on data that is constantly changing, existing methods often lack speed and adaptability to cope with these requirements. This is aggravated by the fact that knowledge graphs are often extremely large and may easily contain millions of entities rendering many of these methods impractical. In this paper, we address the weaknesses of current methods by proposing Random Semantic Tensor Ensemble (RSTE), a scalable ensemble-enabled framework based on tensor factorization. Our proposed approach samples a knowledge graph tensor in its graph representation and performs link prediction via ensembles of tensor factorization. Our experiments on both publicly available datasets and real world enterprise/sales knowledge bases have shown that our approach is not only highly scalable, parallelizable and memory efficient, but also able to increase the prediction accuracy significantly across all datasets.
1st International Workshop on Search and Mining Terrorist Online Content & Advances in Data Science for Cyber Security and Risk on the Web
Authors: Theodora Tsikrika, Babak Akhgar, Vasilis Katos, Stefanos Vrochidis, Pete Burnap, Matthew L. Williams
Venue: WSDM
Year: 2017

The deliberate misuse of technical infrastructure (including the Web and social media) for cyber deviant and cybercriminal behaviour, ranging from the spreading of extremist and terrorism-related material to online fraud and cyber security attacks, is on the rise. This workshop aims to better understand such phenomena and develop methods for tackling them in an effective and efficient manner. The workshop brings together interdisciplinary researchers and experts in Web search, security informatics, social media analysis, machine learning, and digital forensics, with particular interests in cyber security. The workshop programme includes refereed papers, invited talks and a panel discussion for better understanding the current landscape, as well as the future of data mining for detecting cyber deviance.
Modeling Source Code to Support Retrieval-Based Applications
Authors: Venkatesh Vinayakarao
Venue: WSDM
Year: 2017

Advances in text retrieval do not apply directly to source code retrieval because of the difference in characteristics of source code when compared to text. Recently, researchers have proposed specialized indexing and querying techniques that are based on structural representations and semantics of source code. Current tools and techniques heavily depend on user defined terms in source code to leverage text retrieval techniques. Further, they have limitations in handling partial programs, platform independence and index-time processing. We focus on building reusable models of source code for the purposes of indexing and querying.
Partitioning and Segment Organization Strategies for Real-Time Selective Search on Document Streams
Authors: Yulu Wang, Jimmy Lin
Venue: WSDM
Year: 2017

The basic idea behind selective search is to partition a collection into topical clusters, and for each query, consider only a subset of the clusters that are likely to contain relevant documents. Previous work on web collections has shown that it is possible to retain high-quality results while considering only a small fraction of the collection. These studies, however, assume static collections where it is feasible to run batch clustering algorithms for partitioning. In this work, we consider the novel formulation of selective search on document streams (specifically, tweets), where partitioning must be performed incrementally. In our approach, documents are partitioned into temporal segments and selective search is performed within each segment: these segments can either be clustered using batch or online algorithms, and at different temporal granularities. For efficiency, we take advantage of word embeddings to reduce the dimensionality of the document vectors. Experiments with test collections from the TREC Microblog Tracks show that we are able to achieve precision indistinguishable from exhaustive search while considering only around 5% of the collection. Interestingly, we observe no significant effectiveness differences between batch vs. online clustering and between hourly vs. daily temporal segments, despite them being very different index organizations. This suggests that architectural choices should be primarily guided by efficiency considerations.
How Smart Does Your Profile Image Look?: Estimating Intelligence from Social Network Profile Images
Authors: Xingjie Wei, David Stillwell
Venue: WSDM
Year: 2017

Profile images on social networks are users' opportunity to present themselves and to affect how others judge them. We examine what Facebook images say about users' perceived and measured intelligence. 1,122 Facebook users completed a matrices intelligence test and shared their current Facebook profile image. Strangers also rated the images for perceived intelligence. We use automatically extracted image features to predict both measured and perceived intelligence. Intelligence estimation from images is a difficult task even for humans, but experimental results show that human accuracy can be equalled using computing methods. We report the image features that predict both measured and perceived intelligence, and highlight misleading features such as "smiling'' and "wearing glasses'' that are correlated with perceived but not measured intelligence. Our results give insights into inaccurate stereotyping from profile images and also have implications for privacy, especially since in most social networks profile images are public by default.
Recurrent Recommender Networks
Authors: Chao-Yuan Wu, Amr Ahmed, Alex Beutel, Alexander J. Smola, How Jing
Venue: WSDM
Year: 2017

Recommender systems traditionally assume that user profiles and movie attributes are static. Temporal dynamics are purely reactive, that is, they are inferred after they are observed, e.g. after a user's taste has changed or based on hand-engineered temporal bias corrections for movies. We propose Recurrent Recommender Networks (RRN) that are able to predict future behavioral trajectories. This is achieved by endowing both users and movies with a Long Short-Term Memory (LSTM) autoregressive model that captures dynamics, in addition to a more traditional low-rank factorization. On multiple real-world datasets, our model offers excellent prediction accuracy and it is very compact, since we need not learn latent state but rather just the state transition function.
Scalable Text Analysis
Authors: Zijun Xue
Venue: WSDM
Year: 2017

Latent Dirichlet Allocation (LDA) is an extremely popular probabilistic topic model used for a diverse class of appications. While highly effective, one important limitation of LDA is the high memory footprint of its inferencing algorithm, making it difficult to scale to a large dataset. In my thesis, I propose sdLDA, a highly-scalable disk-based LDA that (1) leverages the plentiful space available in disk to reduce its main-memory footprint and (2) preserves the sparsity of the extracted topics during sampling to improve both memory efficiency and sampling complexity of the inferencing algorithm. Our extensive experiments show that sdLDA scales to datasets that are two orders of magnitude larger than what existing main-memory-based algorithms can handle. Furthermore, sdLDA exhibits similar (or even better) performance compared to main-memory-based LDAs in terms of running time.
Predicting Online Purchase Conversion for Retargeting
Authors: Jinyoung Yeo, Sungchul Kim, Eunyee Koh, Seung-won Hwang, Nedim Lipka
Venue: WSDM
Year: 2017

Generally 2% of shoppers make a purchase on the first visit to an online store while the other 98% enjoys only window-shopping. To bring people back to the store and close the deal, "retargeting" has been a vital online advertising strategy that leads to "conversion" of window-shoppers into buyers. As such retargeting is more effective as a focused tool, in this paper, we study the problem of identifying a conversion rate for a given product and its current customers, which is an important analytics metric for retargeting process. Compared to existing approaches using either of customer- or product-level conversion pattern, we propose a joint modeling of both level patterns based on the well-studied buying decision process. To evaluate the effectiveness of our method, we perform extensive experiments on the simulated dataset generated based on a set of real-world web logs. The evaluation results show that conversion predictions by our approach are consistently more accurate and robust than those by existing baselines in dynamic market environment.
Statistical Spoken Dialogue Systems and the Challenges for Machine Learning
Authors: Steve J. Young
Venue: WSDM
Year: 2017

This talk will review the principal components of a spoken dialogue system and then discuss the opportunities for applying machine learning for building robust high performance open-domain systems. The talk will be illustrated by recent work at Cambridge University using machine learning for belief tracking, reward estimation, multi-domain policy learning and natural language generation. The talk will conclude by discussing some of the key challenges in scaling these solutions to work in practical systems.
Temporally Factorized Network Modeling for Evolutionary Network Analysis
Authors: Wenchao Yu, Charu C. Aggarwal, Wei Wang
Venue: WSDM
Year: 2017

The problem of evolutionary network analysis has gained increasing attention in recent years, because of an increasing number of networks, which are encountered in temporal settings. For example, social networks, communication networks, and information networks continuously evolve over time, and it is desirable to learn interesting trends about how the network structure evolves over time, and in terms of other interesting trends. One challenging aspect of networks is that they are inherently resistant to parametric modeling, which allows us to truly express the edges in the network as functions of time. This is because, unlike multidimensional data, the edges in the network reflect interactions among nodes, and it is difficult to independently model the edge as a function of time, without taking into account its correlations and interactions with neighboring edges. Fortunately, we show that it is indeed possible to achieve this goal with the use of a matrix factorization, in which the entries are parameterized by time. This approach allows us to represent the edge structure of the network purely as a function of time, and predict the evolution of the network over time. This opens the possibility of using the approach for a wide variety of temporal network analysis problems, such as predicting future trends in structures, predicting links, and node-centric anomaly/event detection. This flexibility is because of the general way in which the approach allows us to express the structure of the network as a function of time. We present a number of experimental results on a number of temporal data sets showing the effectiveness of the approach.
A Concise Integer Linear Programming Formulation for Implicit Search Result Diversification
Authors: Haitao Yu, Adam Jatowt, Roi Blanco, Hideo Joho, Joemon M. Jose, Long Chen, Fajie Yuan
Venue: WSDM
Year: 2017

To cope with ambiguous and/or underspecified queries, search result diversification (SRD) is a key technique that has attracted a lot of attention. This paper focuses on implicit SRD, where the possible subtopics underlying a query are unknown beforehand. We formulate implicit SRD as a process of selecting and ranking k exemplar documents that utilizes integer linear programming (ILP). Unlike the common practice of relying on approximate methods, this formulation enables us to obtain the optimal solution of the objective function. Based on four benchmark collections, our extensive empirical experiments reveal that: (1) The factors, such as different initial runs, the number of input documents, query types and the ways of computing document similarity significantly affect the performance of diversification models. Careful examinations of these factors are highly recommended in the development of implicit SRD methods. (2) The proposed method can achieve substantially improved performance over the state-of-the-art unsupervised methods for implicit SRD.
PRED: Periodic Region Detection for Mobility Modeling of Social Media Users
Authors: Quan Yuan, Wei Zhang, Chao Zhang, Xinhe Geng, Gao Cong, Jiawei Han
Venue: WSDM
Year: 2017

The availability of massive geo-annotated social media data sheds light on studying human mobility patterns. Among them, periodic pattern, \ie an individual visiting a geographical region with some specific time interval, has been recognized as one of the most important. Mining periodic patterns has a variety of applications, such as location prediction, anomaly detection, and location- and time-aware recommendation. However, it is a challenging task: the regions of a person and the periods of each region are both unknown. The interdependency between them makes the task even harder. Hence, existing methods are far from satisfactory for detecting periodic patterns from the low-sampling and noisy social media data. We propose a Bayesian non-parametric model, named \textbf{P}eriodic \textbf{RE}gion \textbf{D}etection (PRED), to discover periodic mobility patterns by jointly modeling the geographical and temporal information. Our method differs from previous studies in that it is non-parametric and thus does not require priori knowledge about an individual's mobility (\eg number of regions, period length, region size). Meanwhile, it models the time gap between two consecutive records rather than the exact visit time, making it less sensitive to data noise. Extensive experimental results on both synthetic and real-world datasets show that PRED outperforms the state-of-the-art methods significantly in four tasks: periodic region discovery, outlier movement finding, period detection, and location prediction.
Link Prediction with Cardinality Constraint
Authors: Jiawei Zhang, Jianhui Chen, Junxing Zhu, Yi Chang, Philip S. Yu
Venue: WSDM
Year: 2017

Inferring the links among entities in networks is an important research problem for various disciplines. Depending on the specific application settings, the links to be inferred are usually subject to different cardinality constraints, like one-to-one, one-to-many and many-to-many. However, most existing research works on link prediction problems fail to consider such a kind of constraint. In this paper, we propose to study the link prediction problem with general cardinality constraints, which is formally defined as the CLP (Cardinality Constrained Link Prediction) problem. By minimizing the projection loss of links from feature vectors to labels, the CLP problem is formulated as an optimization problem involving multiple variables, where the cardinality constraints are modeled as mathematical constraints on node degrees. The objective function is shown to be not jointly convex and the optimal solution subject to the cardinality constraints can be very time-consuming to achieve. To solve the optimization problem, an iterative variable updating based link prediction framework ITERCLIPS (Iterative Constrained Link Prediction & Selection) is introduced in this paper, which involves the steps on link updating and selection alternatively. To overcome the high time cost problem, a greedy link selection step is introduced in this paper, which picks links greedily while preserving the link cardinality constraints simultaneously. Meanwhile, to ensure the effectiveness of ITERCLIPS on large-scale networks, a distributed implementation of ITERCLIPS is further presented as a scalable solution to the CLP problem. Extensive experiments have been done on three real-world network datasets with different types of cardinality constraints, and the experimental results achieved by ITERCLIPS on all these datasets can demonstrate the effectiveness and advantages of ITERCLIPS in solving the CLP problem.
Enterprise Employee Training via Project Team Formation
Authors: Jiawei Zhang, Philip S. Yu, Yuanhua Lv
Venue: WSDM
Year: 2017

Professional career training for novice employees at elementary levels to help them master necessary working skills is critical for both achieving employees' professional success and enhancing the enterprise growth. Besides adopting professional services from external career training agencies, companies can actually train the employees more effectively by involving them in various internal projects carried out in the companies. In this paper, we will study the "Employee Training" (ET) problem by assigning the employees to various concrete company internal projects. From the company perspective, besides training the employees, another important objective of carrying out these projects is to finish them successfully. The successful accomplishment of projects depends on various issues, like the skill qualification of the built teams and the effective collaboration among the team members. To achieve these two objectives simultaneously, a novel framework named "Team foRmAtion based employee traINing" (TRAIN) is proposed in this paper. TRAIN formulates the ET problem as a joint optimization problem, where the objective function considers the employees' overall skill gain and the team internal communication costs at the same time. To ensure the success of the projects, a new team skill qualification constraint is proposed and added to the optimization problem. Extensive experiments conducted on the real-world enterprise employee project team dataset demonstrate the effectiveness of TRAIN in addressing the problem.