SONIC Lab is proud to welcome Johan Ugander of Stanford University. Dr. Ugander will speak on Tuesday, February 6th, 2017 at 10 AM in Frances Searle Building, Room 1-483. Please contact Dr. Michael Schultz with any questions.
The observation that individuals tend to be friends with people who are similar to themselves, commonly known as homophily, is a prominent and well-studied feature of social networks. While homophily describes a bias in attribute preferences for similar others, it gives limited attention to variability. In this work, we observe that attribute preferences can exhibit variation beyond what can be explained by models of homophily. We call this excess variation monophily to describe the presence of individuals with extreme preferences for a particular attribute possibly unrelated to their own attribute. We observe that monophily can induce a similarity among friends-of-friends on a network without requiring any similarity among friends. In order to independently simulate homophily and monophily in synthetic networks, we contribute a new model of social network structure that we call the overdispersed stochastic block model (oSBM), an extension of the classical stochastic block model. We use this model to demonstrate how homophily-based methods for predicting attributes on social networks based on friends, “the company you keep,” are fundamentally different from monophily-based methods based on friends- of-friends, “the company you’re kept in.” To illustrate the differences between homophily and monophily-based prediction we place particular focus on predicting gender, where homophily can be weak or nonexistent in practice. These findings offer an alternative perspective on network structure and attributes in general and prediction in particular, complicating the already difficult task of protecting privacy on social networks. This is joint work with Kristen Altenburger.
Johan Ugander is an Assistant Professor at Stanford University in the Department of Management Science & Engineering, within the School of Engineering. His research develops algorithmic and statistical frameworks for analyzing social networks, social systems, and other large-scale social data.
Kellogg School of Management, Northwestern University
Expertise Awareness in Multi-Organizational Collaboration: The Role of Goal Awareness
SONIC Lab is proud to welcome Esther Sackett of the Northwestern University. Dr. Sackett will speak on Thursday, December 7th, 2017 at 2 PM in Frances Searle Building, Room 1-483. Please contact Dr. Michael Schultz with any questions.
Multistakeholder alliances typically have dual purposes that are often in tension – 1) pooling knowledge and resources toward a collaborative goal, and 2) engaging in knowledge transfer by leveraging knowledge and resources for each individual organization’s benefit. However, research has also demonstrated that these dual purposes are also quite intertwined, as members’ sustained engagement in the alliance over time depends on the perceived value of participation in terms of meeting their own organization’s needs. Inherent in the structure of multistakeholder alliances and their dual purposes is an implicit assumption: that the distributed expertise in a multistakeholder alliance is available for the pursuit of both collaborative goals and knowledge transfer. However, each of these goals may actually require access to different sets of expertise. Thus, a potentially overlooked mechanism for overcoming the challenges of balancing the dual purposes of multistakeholder alliances may reside in the relationships between the goals being pursued and the mechanisms for accessing the expertise needed to address them. Building on the framework of transactive memory systems, I use a qualitative approach to explore the factors that contribute to the development of expertise awareness, goal awareness, and the relationship between them in a multistakeholder alliance in the healthcare sector.
College of Urban Planning and Public Affairs, University of Illinois at Chicago
Global Policy and Local Networks
The contested resource framework for collaboration and science
SONIC Lab is proud to welcome Michael D. Siciliano of the Univeristy of Illinois at Chicago. Prof. Siciliano speak on Monday, November 13, 2017 at 10:00 AM in Frances Searle Building, Room 1-489. Please contact Dr. Michael Schultz with any questions.
How do institutional changes affect micro-level behaviors? International agreements such as the Nagoya and Cartagena Protocols of the Convention on Biological Diversity (CBD) are resulting in new policy institutions that regulate the global exchange and use of biological materials in research. These rules are shifting the locus of control over materials from individual researchers to institutions that represent stakeholder interests. Traditionally, material resource exchange occurs within social networks that link scientists with other scientists and with provider organizations. In this new context of contested resources, access to and exchange of biological materials are jointly determined by personal networks and the new authority structures that govern the exchange relationships within the networks. Relying on a nationally representative sample of scientists in the United States, this talk explores how institutional controls on resource inputs affect collaboration structures and science production.
D’Amore-McKim School of Business, Northeastern University
Quantifying Patterns of Success in Creative Careers
SONIC Lab is proud to welcome Christoph Riedl of the D’Amore-McKim School of Business at Northeastern University. Prof. Riedl will present a talk on Monday, October 23, 2017 at 10:00 AM in Frances Searle Building, Room 1-489. Please contact Michael Schultz with any questions.
In most areas of human performance, the path to major accomplishments requires a steep learning curve, long practice and many trials. Athletes go through years of training and compete repeatedly before setting new records; musicians practice from an early age and perform in secondary venues before earning the spotlight. Yet, little is known about the quantitative patterns that lead to success in creative fields. In this talk we provide a quantitative framework to describe the evolution of success in artistic careers, and ask: Is the success of a particular artist predictable? Are there network measures that improve our understanding of success? We focus on trajectories followed by visual artists through a network of galleries and museums, and show that the prestige of institutions, quantified through network measures, fully determines an artist’s future success. Starting in prestigious venues increases the chance of exhibiting in more venues, appealing to a more international audience, and of being successful in the auction market.
Christoph Riedl is the Joseph G. Riesman Research assistant professor for Information Systems at the D’Amore-McKim School of Business at Northeastern University. He hold a joint appointment with the College of Computer & Information Science and is a core faculty at the Network Science Institute. He is a fellow at the Institute for Quantitative Social Science (IQSS) at Harvard University. He is recipient of a Young Investigator Award (YIP) from Army Research Office (ARO) for his work on social networks in collaborative decision-making. Before joining Northeastern University he was a post-doctoral fellow at Harvard Business School and IQSS. He received a PhD in Information Systems from Technische Universität München (TUM), Germany in 2011, a MSc in Information Systems in 2007, and a BSc in Computer Science in 2006. His work has been funded by NSF and published in leading journals including Management Science, Information Systems Research, and Academy of Management Discoveries.
SONIC Lab is proud to welcome Ingmar Weber who will present a talk on Wednesday, November 16th, 2016 at 10:00 AM in Frances Searle Building, Room 1-459. Please contact SONIC Lab Manager Katya Bitkin with any questions or comments.
Demographics in Social Networks: Usage Differences, Content Spread, and Homophily
How do demographic attributes affect network structure and content spread? In this talk, I’ll present attempts to address this question using a demographically annotated data set for 350K Twitter users in New York. For each user, their gender, age and race has been inferred from their profile picture using Face++. I’ll start by showing that population-level differences in hashtag usage are intuitive, such as African Americans being more likely to use #blacklivesmatter, women more likely to use #makeup, and young people more likely to use #growingupwithsiblings. Taking ideas previously studied in the context of web search, we then look at which demographic groups are generally first – or last – to use new hashtags. Here we find that, e.g., new music-related hashtags tend to originate from African American users, whereas new baseball hashtags come from white men. Looking at the topic of “algorithmic bias”, we show that the “what’s trending” tends to favor the majority group, potentially creating hurdles for minority content to benefit from system-induced feedback. Finally, I’ll show results related to racial link asymmetries, potentially indicating latent discrimination.
The work presented is joint work with Jisun An at QCRI, and several members of the Social Dynamics Lab (http://sdl.soc.cornell.edu/) at Cornell University, including Michael Macy, George Berry, Minsu Park and Chris Cameron. The research varies in terms of doneness from “medium well” to “rare”. More information on past projects at http://ingmarweber.de/publications/.
Ingmar Weber is a senior scientist in the Social Computing Group at the Qatar Computing Research Institute (QCRI) in Doha. He uses large amounts of online data to address research questions of societal relevance related to (i) lifestyle diseases, (ii) societal fragmentation, and (iii) international migration. He has published over 100 peer-reviewed articles (http://ingmarweber.de/publications/) and his work is frequently featured in the popular press (https://www.google.com/search?tbm=nws&q=%22ingmar+weber%22). Since April 2016 he’s been selected as an ACM Distinguished Speaker.
SONIC Lab is proud to welcome Eric Quintane who will present a talk on Monday, December 5th, 2016 at 10:00 AM in Frances Searle Building, Room 1-483. All are welcome to attend. To schedule a one-on-one meeting with Dr. Quintane please schedule a time HERE. Please contact SONIC Lab Manager Katya Bitkin with any questions or comments.
How do Brokers Broker?
Tertius Gaudens, Tertius Iungens, and the Temporality of Structural Holes
Organizational network research has demonstrated that multiple benefits accrue to people occupying brokerage positions. However, the extant literature offers scant evidence of the process postulated to drive such benefits –information brokerage– and therefore leaves unaddressed the question of brokers broker. We address this gap by examining the information-brokerage interactions in which actors engage. We argue that the information-brokerage strategies of brokers differ in three critical ways from those of actors embedded in denser network positions. First, brokers more often broker information via short-term interactions with colleagues outside their network of long-term relationships, a process we label “unembedded brokerage.” Second, when they engage in unembedded brokerage, brokers are more likely than are actors in dense network positions to intermediate the flow of information between the brokered parties, consistent with a tertius gaudens strategy. Conversely, and third, when they broker information via their network of long-term ties (embedded brokerage), brokers are more likely than are densely connected actors to facilitate a direct information exchange between the brokered parties, consistent with a tertius iungens strategy. Using a relational event model, we find support for our arguments in an empirical analysis of email communications among employees in a medium-sized, knowledge-intensive organization, as well as in a replication study. The theory and evidence we present advance a novel, temporal perspective on how brokers broker, which reconciles structural and process views of network brokerage. Our findings substantiate the notion of brokers as a dynamic force driving change in organizational networks, and they help to integrate within a unitary explanatory framework tertius iungens and tertius gaudens views of brokerage.
Eric Quintane is an associate professor of management at the School of Management, The University of Los Andes, Bogota, Colombia. He received his Ph.D. from the University of Melbourne (Australia). His research interests include dynamics of organizational networks, temporality of social processes, creativity and innovation.
SONIC Lab is proud to welcome Robert Ackland who will present his talk on Tuesday, April 10th, 2016 at 9:00 AM in Frances Searle Building, Room 3-417. All are welcome to attend. To schedule a one-on-one meeting with Dr. Ackland please schedule a time HERE. Join our Facebook Event HERE.
We characterize an online activist field as a social arena in which participants vie for the definition of the most urgent cause or risk issue. We ask the question: to what extent is it conceptually and empirical valid to regard protest activity on Twitter, such as the Occupy Wall Street movement, as an online activist field? Network analysis is used to examine two core aspects of field theory: the behavior of incumbents vs new entrants in response to a new issue or frame, and the dynamics of field formation. This project extends earlier research concerning organizations involved in environmental social movements and online collective identity formation and contributes to emerging research on activism in the era of the “networked individual”.
Robert Ackland is an Associate Professor with a joint appointment in the School of Sociology and the Centre for Social Research and Methods at the Australian National University. He has degrees in economics from the University of Melbourne, Yale University and the ANU, where he gained his PhD on index number theory in the context of cross-country comparisons of income and inequality in 2001, and he has worked as an economist at the Australian Department of Immigration and the World Bank. Since 2002 Robert has been conducting quantitative research into online social and organizational networks, and his research has appeared in journals such as the Review of Economics and Statistics, Social Networks, Computational Economics, Social Science Computer Review, and the Journal of Social Structure. He leads the Virtual Observatory for the Study of Online Networks Lab and he created the VOSON software for hyperlink network construction and analysis, which has been publicly available since 2006 and is used by researchers worldwide. Robert established the Social Science of the Internet specialization in the ANU’s Master of Social Research in 2008, and his book Web Social Science: Concepts, Data and Tools for Social Scientists in the Digital Age (SAGE) was published in 2013. Robert has been chief investigator on five Australian Research Council grants and in 2007, he was a UK National Centre for e-Social Science Visiting Fellow and James Martin Visiting Fellow based at the Oxford Internet Institute. In 2011, he was appointed to the Science Council of the Web Foundation’s Web Index project and he recently contributed a background paper to the World Bank’s World Development Report 2016: Digital Dividends.
SONIC Lab is proud to welcome Corinne Coen who will present a talk on Tuesday, March 29th, 2016 at 9:00 AM in Frances Searle Building, Room 1-483. All are welcome to attend. To schedule a one-on-one meeting with Dr. Coen please schedule a time HERE. Please contact Meghan McCarter with any questions or comments.
The New Foundations: Emergence, Constructionism and the New Reductionism
The science of studying emergence is not well understood among organizational scholars. Scholars often transfer assumptions from variance analysis to this particular application of process analysis. Further, its components parts—emerging, emergent outcomes and their properties—are often confounded leading to muddled thinking. In this paper, I distinguish among these components. Specifically, I discuss the features of complex systems drawing out distinctions between complex vs complicated non-linear systems, constituting vs causing, aggregation, levels, and holism. I draw out the implications of this research approach, emphasizing the paradigm shift required to apply it from other approaches, using examples from organization studies, particularly the Strategy Microfoundations debate.
Corinne Coen is an Associate Professor of Organizational Behavior at Weatherhead School of Management in Case Western Reserve University where she holds the Lewis Progressive Fellowship and is the Chair of the Faculty Council. She has an MBA from University of Chicago and a Ph.D. in Business Administration from the University of Michigan. Her research interests focus on the dynamics of work teams as they generate cooperation and competition, cohesion, and sub-groups. In the pursuit of understanding these dynamic processes, Corinne has special expertise in agent-based modeling and the study of cross-level emergence. Her work has been published in Organizational Science, Organizational Behavior and Human Decision Processes, Computational and Mathematical Organization Theory and Simulation Modeling Practice and Theory.
SONIC Lab is proud to welcome Charles Macal who will present a talk on Tuesday, February 23rd, 2016 at 10:00 AM in Frances Searle Building, Room 1-483. All are welcome to attend. To schedule a one-on-one meeting with Dr. Macal please schedule a time HERE. Please contact Meghan McCarter with any questions or comments.
Simulating Chicago (and Everyone in It)
chiSIM, the Chicago Social Interaction Model, is an agent-based model of people and places in Chicago along with the daily activities in which residents engage. To support planning and policy making, chiSIM models the behaviors and social interactions of all Chicago residents, represented in the model at the individual level. Places consist of geo-located parcels in the city, such as households, schools, workplaces, hospitals, and general quarters, such as nursing homes, dormitories, jails, etc. During the course of a simulated day, agents move from place to place, hour by hour, engaging in social activities and interactions with co-located agents. Examples of applications for this model include forecasting socially mediated processes, such as the spread of infectious diseases and the adoption of new technologies; measuring the potential effectiveness of public health and social programs and interventions; and assessing population-wide energy usage.
Charles Macal, PhD, PE, is Senior Systems Engineer, Argonne Distinguished Fellow, and Group Leader of the Social & Behavioral Systems Group within the Global Security Sciences Division of Argonne National Laboratory. Dr. Macal is recognized globally as a leader in the field of agent-based modeling and simulation and has led interdisciplinary research teams in developing innovative computer simulation models in application areas including global and regional energy markets, critical materials, electric power, healthcare and infectious diseases, environment and sustainability, and technology adoption. Dr. Macal holds Senior Fellow appointments at the Computation Institute (CI) of the University of Chicago and the Northwestern-Argonne Institute for Science and Engineering (NAISE). He received a Ph.D. in Industrial Engineering & Management Sciences from Northwestern University and holds an M.S. in Industrial Engineering and a B.S. in Engineering Sciences from Purdue University.