Events
Past Event
NICO DECEMBER SEMINAR: Scott Feld, Purdue University "Finding Highly Connected Nodes in Networks: The Power of Common Friends"
Northwestern Institute on Complex Systems (NICO)
11:00 AM
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Lower Level, Chambers Hall
Details
Speaker:
Scott Feld, Professor of Sociology, Purdue University
Title:
Finding Highly Connected Nodes in Networks: The Power of Common Friends
Abstract:
This paper extends the Friendship Paradox – where friends have more friends than random people do, on average – to the more general phenomenon that mutual friends have more friends than friends do, on average. We show that we can find people who who are friends of multiple people in practical sized random samples in one regional Facebook network of 63,392 people with an average of 24 friends each, where people with two friends in a random sample have an average of 212 friends overall, with three friends have an average of 391 friends, etc. We further illustrate this general network phenomenon by taking random samples of citations from 79,034 journal articles. We find that a source cited by two articles in a random sample has an average of 461 citations, placing it in the top 0.01% in numbers of citations among all sources cited by these articles. We provide a general expression for the expected overall number of friends of a person found to have k friends in a random sample from a population with a given distribution of numbers of friends. We show that the effectiveness of using common friends among random samples for finding highly connected nodes is most pronounced when there are nodes with a great disproportion of the ties, as seems to be both typical and important for many types of social and other networks, such as where there are superspreaders of diseases, mega-influencers on the Internet, and highly connected central nodes in centralized neural networks. We discuss further implications, applications, and directions for further research.
Speaker Bio:
Scott Feld served as Assistant to Full Professor of Sociology at the State University of New York at Stony Brook from 1975-1991. He then served as Professor of Sociology at Louisiana State University from 1991 until 2004, and joined the faculty at Purdue University in 2004. He has published over sixty articles, including twelve published in the most prestigious journals in the fields of Sociology and Political Science. His ongoing research interests involve 1) causes and consequences of patterns in social networks, 2) processes of individual and collective decision making, and 3) applications of sociology, most recently including innovations in marriage and divorce laws (covenant marriage). He regularly teaches undergraduate and graduate courses on social networks, research methods, and statistics.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/91453237911
Passcode: NICO2024
Time
Tuesday, December 3, 2024 at 11:00 AM - 12:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Data Science Nights - January 2026 - Speaker: Moh Hosseinioun, Kellogg School of Management
Northwestern Institute on Complex Systems (NICO)
5:30 PM
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M416, Technological Institute
Details
JANUARY MEETING: Thursday, January 29, 2026 at 5:30pm (US Central)
NEW LOCATION:
ESAM Conference Room, Tech M416
2145 Sheridan Road, Evanston, IL 60208
AGENDA:
5:30pm - Meet and greet with refreshments
6:00pm - Talk with Moh Hosseinioun, PhD, Alfred Sloan Foundation Postdoctoral Fellow, Kellogg School of Management and Northwestern Institute on Complex Systems
TALK TITLE:
AI Reshapes the Practice of Science: Evidence from Two Decades of Research Proposals
ABSTRACT:
This project draws on a proprietary corpus of full-text and budgetary data from all (accepted and rejected) grant proposals submitted over the past two decades to a major research funding agency, offering a rare empirical lens for assessing the economic and scientific returns on investment (ROI) in Artificial Intelligence (AI). Using large language models (LLMs), we systematically classify proposals by AI engagement, distinguishing algorithmic types (e.g., simple nearest neighbor classifier vs. deep neural networks) and depth of integration (e.g., mentioning an algorithm as a benchmark vs. applying AI for inference). We link these classifications to highly granular budget data to examine how AI reshapes scientific production, reallocating funding across human capital costs, equipment and operational expenses, and overhead. Beyond resource allocation, we analyze project design, team size, duration, and applicant profiles, to study how AI alters the organization and execution of research. Leveraging both funded and unfunded proposals, we estimate the impact of AI use on proposal success, research output, and downstream career outcomes. This allows us to quantify not just the direct benefits of AI for scientific discovery, but also the opportunity costs and career implications for researchers adopting AI. Beyond offering unique insights into how AI reshapes the practice of science, our results contribute to emerging frameworks in the economics of science and innovation policy. In doing so, we offer practical insights into which types of AI investment yield sustained returns at the institutional and individual level, and where investments may be driven more by hype than value.
DATA SCIENCE NIGHTS are monthly meetings featuring presentations and discussions about data-driven science and complex systems, organized by Northwestern University graduate students and scholars. Students and researchers of all levels are welcome! For more information: http://bit.ly/nico-dsn
FUTURE DATES:
Data Science Nights will be held on Thursday evenings in the winter and spring terms, on February 26, March 19, April 30, and May 28, 2026.
Time
Thursday, January 29, 2026 at 5:30 PM - 7:30 PM
Location
M416, Technological Institute Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO Winter Seminar Series returns on February 4th!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
The Wednesdsays@NICO speaker series will return for the winter quarter on February 4th, 2026, running through March 11th. Speakers will be announced in January!
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: Zoom links will be provided
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, February 4, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)