ICWSM-17 Technical Program

The ICWSM-17 technical program will be held in the Grand Salon Opera B/C on Level 4 of the Hyatt, May 16-18. Each author has been allotted 18 minutes for oral presentations, including 3 minutes for Q&A.

Tuesday, May 16

9:00 – 9:15 AM: Awards and Opening Remarks

Derek Ruths, General Chair, ICWSM-17

9:15 – 10:15 AM: Keynote Address:

Matt Salganik (Princeton University)

Beyond Big Data

The digital age has transformed how we are able to study social behavior. Unfortunately, researchers have not yet taken full advantage of these opportunities because we are too focused on “big data,” such as digital traces of behavior. These big data can be wonderful for some research questions, but they have fundamental limitations for addressing many questions because they were never designed to be used for research. This talk will argue that rather than focusing on “found data”, researchers should use the capabilities of the digital age to create new forms of “designed data.” This talk is based on my forthcoming book—Bit by Bit: Social Research in the Digital Age—which is currently in Open Review at http://www.bitbybitbook.com.

10:15 – 10:45 AM: Coffee Break

10:45 AM – 12:35 PM: Paper Session I: Digital Currency

Cold Hard E-Cash: Friends and Vendors in the Venmo Digital Payments System
Xinyi Zhang, Shiliang Tang, Yun Zhao, Gang Wang, Haitao Zheng, Ben Y. Zhao

The Rich Get Richer? Limited Learning in Charitable Giving on donorschoose.org
Chankyung Pak, Rick Wash

When Does More Money Work? Examining the Role of Perceived Fairness in Pay on the Performance Quality of Crowdworkers
Teng Ye, Sangseok You, Lionel P. Robert Jr.

Echo Chambers in Investment Discussion Boards
Shiliang Tang, Qingyun Liu, Megan McQueen, Scott Counts, Apurv Jain, Haitao Zheng, Ben Zhao

Online Popularity under Promotion: Viral Potential, Forecasting, and the Economics of Time
Marian-Andrei Rizoiu, Lexing Xie Xie

The Misleading Narrative of the Canonical Faculty Productivity Trajectory
Samuel Way, Allison Morgan, Aaron Clauset, Daniel Larremore

12:35 – 2:00 PM: Hosted Lunch

Grand Salon Opera A

2:00 – 3:15 PM: ICWSM-17 Panel: Politics and News in a Networked Age

Panelists: Craig Silverman (Media Editor, Buzzfeed), Kate Starbird (Assistant Professor, Department of Human Centered Design & Engineering, University of Washington), and Thomas Pitfield (President, Data Sciences)

Social media has changed how news and political information circulates. People spread articles and activist alerts across platforms like Facebook and Twitter, but this includes "fake news," misinformation, and even disinformation. While political campaigns can use Big Data to target potential voters and spread their messaging, they must confront the ability of participatory media to amplify rumors and conspiracy theories. In this panel, participants share their expertise in journalism, activism, and politics, and discuss the challenges that new forms of media bring to information in a digital age.

3:15 – 3:45 PM: Session II: Dataset Papers

Fashion Conversation Data on Instagram
Yu-I Ha, Sejeong Kwon, Meeyoung Cha, Jungseock Joo

TokTrack: A Complete Token Provenance and Change Tracking Dataset for the English Wikipedia
Fabian Flöck, Kenan Erdogan, Maribel Acosta

Data Sets: Word Embeddings Learned from Tweets and General Data
Quanzhi Li, Sameena Shah, Xiaomo Liu, Armineh Nourbakhsh

EmojiNet: An Open Service and API for Emoji Sense Discovery
Sanjaya Wijeratne, Lakshika Balasuriya, Amit Sheth, Derek Doran

3:45 – 4:00 PM: Coffee Break

4:00 – 6:10 PM: Paper Session III: Online Communities

Community Identity and User Engagement in a Multi-Community Landscape
Justine Zhang, William L. Hamilton, Cristian Danescu-Niculescu-Mizil, Dan Jurafsky, Jure Leskovec

Why Do Men Get More Attention? Exploring Factors behind Success in an Online Design Community
Johannes Wachs, Aniko Hannak, András Vörös, Bálint Daróczy

Characterizing Online Discussion Using Coarse Discourse Sequences
Amy X. Zhang, Bryan Culbertson, Praveen Paritosh

To Thread or Not to Thread: The Impact of Conversation Threading on Online Discussion
Pablo Aragón, Vicenç Gómez, Andreas Kaltenbrunner

To Help or Hinder: Real-Time Chat in Citizen Science
Ramine Tinati, Elena Simperl, Markus Luczak-Roesch

Which Size Matters? Effects of Crowd Size on Solution Quality in Big Data Q&A Communities
Yla Tausczik, Ping Wang, Joohee Choi

Better When It Was Smaller? Community Content and Behavior after Massive Growth
Zhiyuan Lin, Niloufar Salehi, Bowen Yao, Yiqi Chen, Michael S. Bernstein

7:00 – 9:00 PM: ICWSM-17 Opening Reception

Place des Arts, Salon Urbain, 175 Sainte-Catherine West, Montreal

Wednesday, May 17

9:00 – 10:00 AM: Keynote Address:

Lorrie Cranor (Carnegie Mellon University)

The Art of Privacy

In this talk I will explore privacy through art. I will show examples of privacy-related artwork created by myself and by other artists, as well as common privacy visualizations. Then I will discuss the Privacy Illustrated project, in which we invite everyday people to draw pictures of privacy and what it means to them.  The material we have collected from children and adults is illustrative of American views on privacy over the past few years – including contributors’ thoughts on physical privacy, information privacy, surveillance, privacy on social networks, and more. It offers insights into how people conceptualize privacy, and suggests symbols that convey privacy concepts.

10:00 – 10:35 AM: Paper Session IV: Best Paper Candidates

Examining the Alternative Media Ecosystem through the Production of Alternative Narratives of Mass Shooting Events on Twitter
Kate Starbird

Kek, Cucks, and God Emperor Trump: A Measurement Study of 4chan's Politically Incorrect Forum and Its Effects on the Web
Gabriel Emile Hine, Jeremiah Onaolapo, Emiliano De Cristofaro, Nicolas Kourtellis, Ilias Leontiadis, Riginos Samaras, Gianluca Stringhini, Jeremy Blackburn

10:35 – 11:00 AM: Coffee Break

11:00 AM– 12:30 PM: Paper Session V: News and Networks

Armed Conflicts in Online News: A Multilingual Study
Robert West, Jürgen Pfeffer

State of the Geotags: Motivations and Recent Changes
Dan Tasse, Zichen Liu, Alex Sciuto, Jason Hong

Online Human-Bot Interactions: Detection, Estimation, and Characterization
Onur Varol, Emilio Ferrara, Clayton A. Davis, Filippo Menczer, Alessandro Flammini

Wearing Many (Social) Hats: How Different Are Your Different Social Network Personae?
Changtao Zhong, Hau-wen Chang, Dmytro Karamshuk, Dongwon Lee, Nishanth Sastry

How Editorial, Temporal and Social Biases Affect Online Food Popularity and Appreciation
Markus Rokicki, Eelco Herder, Christoph Trattner

12:30 – 2:00 PM: Lunch Break

2:00 – 3:00 PM: ICWSM-17 Panel: The Ethics of Social Data

Panelists: Mary Gray (Senior Researcher at Microsoft Research, Fellow at the Berkman Center for Internet and Society and Associate Professor of the Media School at Indiana University) and Jeff Hancock (Professor, Department of Communication, Stanford University)

In this panel, two senior scholars discuss the ethical complexity of Big Data. While social media has provided computer scientists and social scientists alike with a rich trove of personal information, scholarly communities are grappling with how to use this data ethically. Guidelines and institutional review boards designed in an era of "small data" do not provide appropriate guidance for questions of informed consent, privacy protection, and accountability. This panel delves into the issues around big social data and discusses different approaches and possible solutions.

3:00 – 4:15 PM: Paper Session VI: Biases and Abuse

Who Makes Trends? Understanding Demographic Biases in Crowdsourced Recommendations
Abhijnan Chakraborty, Johnnatan Messias, Fabricio Benevenuto, Saptarshi Ghosh, Niloy Ganguly, Krishna P. Gummadi

Identifying Effective Signals to Predict Deleted and Suspended Accounts on Twitter across Languages
Svitlana Volkova, Eric Bell

Adaptive Spammer Detection with Sparse Group Modeling
Liang Wu, Xia Hu, Fred Morstatter, Huan Liu

“Be Careful; Things Can Be Worse than They Appear”: Understanding Biased Algorithms and Users’ Behavior around Them in Rating Platforms
Motahhare Eslami, Kristen Vaccaro, Karrie Karahalios, Kevin Hamilton

4:15 – 6:00 PM: ICWSM-17 Poster/Demo Session

Grand Salon Opera A

Light refreshments will be served.

Posters

Recognizing Pathogenic Empathy in Social Media
Muhammad M. Abdul-Mageed, Anneke Buffone, Hao Peng, Johannes Eichstaedt, Lyle Ungar

On Quitting: Performance and Practice in Online Game Play
Tushar Agarwal, Keith Burghardt, Kristina Lerman

QT2S: A System for Monitoring Road Traffic via Fine Grounding of Tweets
Noora Al Emadi, Sofiane Abbar, Javier Borge-Holthoefer, Francisco Guzman, Fabrizio Sebastiani

Are There Gender Differences in Professional Self-Promotion? An Empirical Case Study of LinkedIn Profiles among Recent MBA Graduates
Kristen M. Altenburger, Rajlakshmi De, Kaylyn Frazier, Nikolai Avteniev, Jim Hamilton

25 Tweets to Know You: A New Model to Predict Personality with Social Media
Pierre-Hadrien Arnoux, Anbang Xu, Neil Boyette, Jalal Mahmud, Rama Akkiraju, Vibha Sinha

What Gets Media Attention and How Media Attention Evolves over Time — Large-Scale Empirical Evidence from 196 Countries
Jisun An, Haewon Kwak

Separating the Wheat from the Chaff: Evaluating Success Determinants for Online Q&A Communities
Erik Aumayr, Conor Hayes

Identifying Leading Indicators of Product Recalls from Online Reviews using Positive Unlabeled Learning and Domain Adaptation
Shreesh Kumara Bhat, Aron Culotta

Is Slacktivism Underrated? Measuring the Value of Slacktivists for Online Social Movements
Lia Bozarth, Ceren Budak

Exploiting Contextual Information for Fine-Grained Tweet Geolocation
Wen-Haw Chong, Ee-Peng Lim

Nasty, Brutish, and Short: What Makes Election News Popular on Twitter?
Sophie Chou, Deb Roy

A Motif-Based Approach for Identifying Controversy
Mauro Coletto, Kiran Garimella, Aristides Gionis, Claudio Lucchese

‘Just the Facts’: Exploring the Relationship between Emotional Language and Member Satisfaction in Enterprise Online Communities
Ryan James Compton, Jilin Chen, Eben Haber, Hernan Badenes, Steve Whittaker

Suitable for All Ages: Using Reviews to Determine Appropriateness of Products
Elizabeth M. Daly, Oznur Alkan, Michael Muller

How Fast Will You Get a Response? Predicting Interval Time for Reciprocal Link Creation
Vachik S. Dave, Mohammad Al Hasan, Chandan K. Reddy

Automated Hate Speech Detection and the Problem of Offensive Language
Thomas Davidson, Dana Warmsley, Michael Macy, Ingmar Weber

A Gendered Analysis of Leadership in Enterprise Social Networks
Giorgia Di Tommaso, Giovanni Stilo, Paola Velardi

Dynamics of Content Quality in Collaborative Knowledge Production
Emilio Ferrara, Nazanin Alipoufard, Keith Burghardt, Chiranth Gopal, Kristina Lerman

The Ebb and Flow of Controversial Debates on Social Media
Kiran Garimella, Gianmarco De Francisci Morales, Aristides Gionis, Michael Mathioudakis

A Long-Term Analysis of Polarization on Twitter
Venkata Rama Kiran Garimella, Ingmar Weber

Spam Users Identification in Wikipedia via Editing Behavior
Thomas Green, Francesca Spezzano

Antagonism Also Flows through Retweets: The Impact of Out-of-Context Broadcasts in Opinion Polarization Analysis
Pedro Calais Guerra, Roberto Nalon, Renato Assunção, Wagner Meira Jr.

Loyalty in Online Communities
William L Hamilton, Justine Zhang, Cristian Danescu-Niculescu-Mizil, Dan Jurafsky, Jure Leskovec

“Voters of the Year”: 19 Voters Who Were Unintentional Election Poll Sensors on Twitter
William Hobbs, Lisa Friedland, Kenneth Joseph, Oren Tsur, Stefan Wojcik, David Lazer

A World of Difference: Divergent Word Interpretations among People
Tianran Hu, Ruihua Song, Maya Abtahian, Philip Ding, Xing Xie, Jiebo Luo

Mood Congruence or Mood Consistency? Examining Aggregated Twitter Sentiment towards Ads in 2016 Super Bowl
Yuheng Hu, Tingting Nian, Cheng Chen

A Longitudinal Study of Topic Classification on Twitter
Zahra Iman, Scott Sanner, Mohamed Reda Bouadjenek, Lexing Xie

Modeling of Political Discourse Framing on Twitter
Kristen Johnson, Di Jin, Dan Goldwasser

Behavioral Analysis of Review Fraud: Linking Malicious Crowdsourcing to Amazon and Beyond
Parisa Kaghazgaran, James Caverlee, Majid Alfifi

How to Manipulate Social Media: Analyzing Political Astroturfing Using Ground Truth Data from South Korea
Franziska B. Keller, David Schoch, Sebastian Stier, JungHwan Yang

US Presidential Election: What Engaged People on Facebook
Milad Kharratzadeh, Deniz Ustebay

Face-to-BMI: Using Computer Vision to Infer Body Mass Index on Social Media
Enes Kocabey, Mustafa Camurcu, Ferda Ofli, Yusuf Aytar, Javier Marin, Antonio Torralba, Ingmar Weber

From Camera to Deathbed: Understanding Dangerous Selfies on Social Media
Hemank Lamba, Varun Bharadhwaj, Mayank Vachher, Divyansh Agarwal, Megha Arora, Niharika Sachdeva, Ponnurangam Kumaraguru

Controlling for Unobserved Confounds in Classification Using Correlational Constraints
Virgile Landeiro, Aron Culotta

Scalable News Slant Measurement Using Twitter
Huyen Thi Thanh Le, Zubair Shafiq, Padmini Srinivasan

Understanding How People Attend to and Engage with Foreign Language Posts in Multilingual Newsfeeds
Hajin Lim, Susan R. Fussell

Fostering User Engagement: Rhetorical Devices for Applause Generation Learnt from TED Talks
Zhe Liu, Anbang Xu, Mengdi Zhang, Jalal Mahmud, Vibha Sinha

Distinguishing the Wood from the Trees: Contrasting Collection Methods to Understand Bias in a Longitudinal Brexit Twitter Dataset
Clare Llewellyn, Laura Cram

Sparse Overlap Cross-Platform Recommendation via Adaptive Similarity Structure Regularization
Hanqing Lu, Chaochao Chen, Qinyue Jiang

A Computational Approach to Perceived Trustworthiness of Airbnb Host Profiles
Xiao Ma, Trishala Neeraj, Mor Naaman

Detecting the Hate Code on Social Media
Rijul Magu, Kshitij Joshi, Jiebo Luo

Language Use Matters: Analysis of the Linguistic Structure of Question Texts Can Characterize Answerability in Quor
Suman Kalyan Maity, Aman Kharb, Animesh Mukherjee

The Role of Optimal Distinctiveness and Homophily in Online Dating
Danaja Maldeniya, Arun Varghese, Toby Stuart, Daniel Romero

Two-Phase Influence Maximization in Social Networks with Seed Nodes and Referral Incentives
Sneha Mondal, Swapnil Dhamal, Y. Narahari

Predicting Movie Genre Preferences from Personality and Values of Social Media Users
Md. Saddam Hossain Mukta, Euna Mehnaz Khan, Mohammed Eunus Ali, Jalal Mahmud

Automatically Identifying Good Conversations Online (Yes, They Do Exist!)
Courtney Napoles, Aasish Pappu, Joel Tetreault

Robust Classification of Crisis-Related Data on Social Networks using Convolutional Neural Networks
Dat Tien Nguyen, Kamela Ali Al Mannai, Shafiq Joty, Hassan Sajjad, Muhammad Imran, Prasenjit Mitra

Fertility and its Meaning: Evidence from Search Behavior
Jussi Ojala, Emilio Zagheni, Francesco Billari, Ingmar Weber

Inverse Dynamical Inheritance in Stack Exchange Taxonomies
César A. Ojeda, Kostadin Cvejoski, Rafet Sifa, Christian Bauckhage

Changes in Social Media Behavior during Life Periods of Uncertainty
Xinru Page, Marco Marabelli

DeepCity: A Feature Learning Framework for Mining Location Check-ins
Jun Pang, Yang Zhang

Headlines Matter: Using Headlines to Predict the Popularity of News Articles on Twitter and Facebook
Alicja Piotrkowicz, Vania Dimitrova, Jahna Otterbacher, Katja Markert

Ranking with Social Cues: Integrating Online Review Scores and Popularity Information Pantelis Pipergias Analytis, Alexia Delfino, Juliane Kämmer, Mehdi Moussaid, Thorsten Joachims

Querying Documents Annotated by Interconnected Entities
Shouq Sadah, Moloud Shahbazi, Vagelis Hristidis

What Comments Did I Get? How Post and Comment Characteristics Predict Interaction Satisfaction on Facebook
Shruti Sannon, Yoon Hyung Choi, Jessie G. Taft, Natalya N. Bazarova

Towards Measuring Fine-Grained Diversity Using Social Media Photographs
Vivek Kumar Singh, Saket Hegde, Akanksha Atrey

Measuring, Predicting and Visualizing Short-Term Change in Word Representation and Usage in VKontakte Social Network
Ian Stewart, Dustin Arendt, Eric Bell, Svitlana Volkova

Characteristics of On-Time and Late Reward Delivery Projects
Thanh D. Tran, Kyumin Lee

On the Interpretability of Thresholded Social Networks
Oren Tsur, David Lazer

Mapping Twitter Conversation Landscapes
Soroush Vosoughi, Prashanth Vijayaraghavan, Ann Yuan, Deb Roy

Designing a Social Support System for College Adjustment and Social Support
Donghee Yvette Wohn, Mousa Ahmadi, Leiping Gong, Indraneel Kulkarni, Atisha Poojari

Early Identification of Personalized Trending Topics in Microblogging
Liang Wu, Xia Hu, Huan Liu

Detecting Camouflaged Content Polluters
Liang Wu, Xia Hu, Fred Morstatter, Huan Liu

A First Look at User Switching Behaviors Over Multiple Video Content Providers
Huan Yan, Tzu-Heng Lin, Gang Wang, Yong Li, Haitao Zheng, Depeng Jin, Ben Zhao

Self-Disclosure and Channel Difference in Online Health Support Groups
Diyi Yang, Zheng Yao, Robert Kraut

Should We Be Confident in Peer Effects Estimated from Social Network Crawls?
Jiasen Yang, Bruno Ribeiro, Jennifer Neville

Twitter911: A Cautionary Tale
Anis Zaman, Nabil Hossain, Henry Kautz

Event Organization 101: Understanding Latent Factors of Event Popularity
Shuo Zhang, Qin Lv

Detecting Socio-Economic Impact of Cultural Investment through Geo-Social Network Analysis
Xiao Zhou, Desislava Hristova, Anastasios Noulas, Cecilia Mascolo

Demos

Visualizing Health Awareness in the Middle East
Matheus Lima Diniz Araujo, Yelena Mejova, Michael Aupetit, Ingmar Weber

Programming Languages in GitHub: A Visualization in Hyperbolic Plane
Dorota Celińska, Eryk Kopczyński

CitizenHelper: A Streaming Analytics System to Mine Citizen and Web Data for Humanitarian Organizations
Prakruthi Karuna, Mohammad Rana, Hemant Purohit

Junet: A Julia Package for Network Research
Igor Zakhlebin 

Thursday, May 18

9:00 – 10:00 AM: Keynote Address: Hilary Mason (Fast Forward Labs)

Hilary Mason is the founder and CEO of Fast Forward Labs, a machine intelligence research company, and the Data Scientist in Residence at Accel, advising companies large and small on their data strategy. Previously, she spent four years as the Chief Scientist at bitly, leading a team that studied attention on the internet in realtime, doing a mix of research, exploration, and engineering. She co-founded HackNY, a non-profit that helps talented engineering students find their way into the startup community of creative technologists in New York City. She is a co-host DataGotham, and is a member of NYCResistor. She an advisor for several organizations, including Mortar, knod.es, collective[i], and DataKind. She is also a mentor to Betaspring, the Providence, Rhode Island-based startup accelerator, and the Harvard Business School Digital Initiative. She was a member of Mayor Bloomberg's Technology and Innovation Advisory Council, which was a fascinating way to learn how government and industry can work together. She is the recipient of multiple awards, including the TechFellows Engineering Leadership award, and was on the Forbes 40 under 40 Ones to Watch list and Crain's New York 40 under Forty list.

10:00 – 10:35 AM: Paper Session VII: Best Paper Candidates

The Substantial Interdependence of Wikipedia and Google: A Case Study on the Relationship between Peer Production Communities and Intelligent Technologies
Connor McMahon, Isaac Johnson, Brent Hecht

The Language of Social Support in Social Media and its Effect on Suicidal Ideation Risk
Munmun De Choudhury, Emre Kiciman

10:35 – 11:00 AM: Coffee Break

11:00 AM – 12:15 PM: Paper Session VIII: Wikipedia

The Evolution and Consequences of Peer Producing Wikipedia's Rules
Brian Keegan, Casey Fiesler

Analysing Timelines of National Histories across Wikipedia Editions: A Comparative Computational Approach
Anna Samoilenko, Florian Lemmerich, Katrin Weller, Maria Zens, Markus Strohmaier

Spatio-temporal Analysis of Reverted Wikipedia Edits
Johannes Kiesel, Martin Potthast, Matthias Hagen, Benno Stein

Shocking the Crowd: The Effect of Censorship Shocks on Chinese Wikipedia
Ark Fangzhou Zhang, Danielle Livneh, Ceren Budak, Lionel Robert, Daniel Romero

12:15 – 1:45 PM: Lunch Break

12:45 – 1:45 PM: Town Hall Meeting

1:45 – 3:10 PM: Paper Session IX: Gender and Health

Changes in Social Media Affect, Disclosure, and Sociality for a Sample of Transgender Americans in 2016's Political Climate
Oliver L. Haimson, Gillian R. Hayes

Gendered Conversation in a Social Game-Streaming Platform
Supun Nakandala, Giovanni Luca Ciampaglia, Norman Makoto Su, Yong-Yeol Ahn

#NotOkay: Understanding Gender-Based Violence in Social Media
Mai ElSherief, Elizabeth Belding, Dana Nguyen

The Power of the Patient Voice: Learning Indicators of Hormonal Therapy Adherence from an Online Breast Cancer Forum
Zhijun Yin, Bradley Malin, Jeremy Warner, Pei-Yun Hsueh, Ching-Hua Chen

How User Condition Affects Community Dynamics in a Forum on Autism
Mattia Samory, Cinzia Pizzi, Enoch Peserico

3:10 – 3:40 PM: Coffee Break

3:40 – 6:05 PM: Paper Session X: Visual Culture

Cultural Diffusion and Trends in Facebook Photographs
Quanzeng You, Darío García-García, Manohar Paluri, Jiebo Luo, Jungseock Joo

Tracing the Use of Practices through Networks of Collaboration
Rahmtin Rotabi, Cristian Danescu-Niculescu-Mizil, Jon Kleinberg

Selfie-Presentation in Everyday Life: A Large-Scale Characterization of Selfie Contexts on Instagram
Julia Deeb-Swihart, Christopher Polack, Eric Gilbert, Irfan Essa

Predicting Popular and Viral Image Cascades in Pinterest
Jinyoung Han, Daejin Choi, Jungseock Joo, Chen-Nee Chuah

Cultural Values and Cross-Cultural Video Consumption on YouTube
Minsu Park, Jaram Park, Young Min Baek, Michael Macy

Spice Up Your Chat: The Intentions and Sentiment Effects of Using Emojis
Tianran Hu, Han Guo, Hao Sun, Thuy-vy Thi Nguyen, Jiebo Luo

Untangling Emoji Popularity through Semantic Embeddings
Wei Ai, Xuan Lu, Xuanzhe Liu, Ning Wang, Gang Huang, Qiaozhu Mei

Understanding Emoji Ambiguity in Context: The Role of Text in Emoji-Related Miscommunication
Hannah Miller, Daniel Kluver, Jacob Thebault-Spieker, Loren Terveen, Brent Hecht

6:05 – 6:20 PM: Closing Remarks: Derek Ruths, General Chair, ICWSM-17