New NERDS paper: Quantifying Ideological Polarization on a Network

Today we published a paper on ideological polarization. Special congrats to Marilena for this being her first paper!

Quantifying Ideological Polarization on a Network Using Generalized Euclidean Distance, by M. Hohmann, K. Devriendt, M. Coscia, published in Science Advances


An intensely debated topic is whether political polarization on social media is on the rise. We can investigate this question only if we can quantify polarization, by taking into account how extreme the opinions of the people are, how much they organize into echo chambers, and how these echo chambers organize in the network. Current polarization estimates are insensitive to at least one of these factors: they cannot conclusively clarify the opening question. Here, we propose a measure of ideological polarization which can capture the factors we listed. The measure is based on the Generalized Euclidean (GE) distance, which estimates the distance between two vectors on a network, e.g., representing people’s opinion. This measure can fill the methodological gap left by the state of the art, and leads to useful insights when applied to real-world debates happening on social media and to data from the US Congress.

NERDS growth in 2023

Happy new year! We are excited to report many new faces at NERDS, on one hand due to an increased number of interns joining, and on the other hand through Luca’s Carlsberg grant which now starts to kick in.

With Jan 1st, joining us is the new long-term member Arianna Pera as PhD student, who recently got her master degree at Universita Bicocca in Italy. She will work in the area of computational social science, and especially with topics related to coordination. At the same time, we have postdoc Alessia Antelmi from University of Salerno in Italy. She will be with us for 6 months working on higher-order interactions applied to online conversations. Further, Lucio La Cava is a PhD student at the University of Calabria in Italy. He will visit us for three months, working at the intersection of collective coordination and Web3. A future PhD student will be Anders Giovanni Møller, who is currently still a Masterstudent here at ITU. He will start his PhD with us in June but he is already around before then. His main focus is NLP and he will work at the intersection of NLP and social network analysis. Apart from this new batch of 2023 people, we have two more master student interns, Henrik Wolf and Carlson Büth, who are visiting us since fall from Germany, Dresden and Münster, respectively.

All of these excellent new people bring more life to our group – they also have almost filled up all our tables in our large 3F29 section and we might need to look for new space soon. We are happy about all the buzz and intellectual cross-pollination going on!

Our interns are happy and becoming numerous due to our group’s and university’s efforts to be welcoming to visitors. To quote our Positions page:

We are very open to welcome self-funded research visitors if the topic of collaboration makes sense – for such inquiries please contact us via email. If you need funding let us know too: There might be / we might know of possibilities of third-party or internal funding.

Stonks 📈

Arianna Pera has joined NERDS

We are thrilled to welcome Arianna Pera to NERDS!

Arianna will be a PhD student for 3 years, working with Luca Aiello on the Carlsbergfondet project COCOONS on fostering collective cooperation in online social media to tackle societal dilemmas. Arianna recently got her MSc in Data Science from Università degli Studi di Milano-Bicocca. She will work at the intersection of Network Science and Natural Language Processing. Welcome, Arianna!

 

 

New NERDS paper: Multidimensional tie strength and economic development

Multidimensional tie strength and economic development, by L.M. Aiello, S. Joglekar, and D. Quercia, published in Scientific Reports

For decades, Granovetter’s tie strength has been quantified using the frequency of interaction. Yet, frequency does not reflect Granovetter’s initial conception of strength, which is a mix of social dimensions including exchnage of knowledge and provision of support. We used Natural Language Processing to quantify whether text messages convey expressions of knowledge or support, and applied it to a large conversation network from of Reddit users resident in the United States. Borrowing a classic experimental setup, we tested whether the diversity of social connections of Reddit users resident in a specific US state would correlate with the economic opportunities in that state (estimated with GDP per capita). We found that the combination of diversity calculated on the knowledge and support networks correlates much more strongly with GDP than diversity calculated on a network weighted with interaction frequency (R2=0.62 vs. R2=0.30). We also found that the two types of ties differ in their geographical span. Knowledge ties are long-distance (i.e., connecting people living in far-away states), support ties are mostly created among people living close by. Read more in this blogpost.

New NERDS paper: Computational Desire Line Analysis of Cyclists

We published another urban planning paper:

  1. Computational Desire Line Analysis of Cyclists on the Dybbølsbro Intersection in Copenhagen, by S.M. Breum, B. Kostic, and M. Szell, published in Transport Findings

    To improve intersection planning, here we develop a computational method to detect cyclist trajectories from video recordings and apply it to the Dybbølsbro intersection in Copenhagen, Denmark. In one hour of footage we find hundreds of trajectories that contradict the design, explainable by the desire for straightforward, uninterrupted travel largely not provided by the intersection. This neglect and the prioritization of vehicular traffic highlight opportunities for improving Danish intersection design.

Luigi Arminio has joined NERDS

We are happy to welcome Luigi Arminio to our research group!

Luigi joins us as PhD student for 3 years. He’ll be supervised by Luca Rossi and work on the EU-funded PolarVis project on online propagation of visual narratives in the context of climate change communication. Luigi achieved his MSc in Data Science at the University of Trento with a research thesis, realized in collaboration with the Fondazione Bruno Kessler, in which he investigated the flow of information (and misinformation) about Covid-19 in the Italian context by means of NLP and Network Science techniques. 

 

DataBeers Copenhagen is back!

Copenhagen’s third DataBeers edition was held this wednesday, more than 3(!) years after the first two editions before COVID-19. The event was once again a smashing success, with around 90 participants, 5 excellent speakers from academia and industry, one surprise data rapper, and a large number of hoppy beverages consumed.

Huge thanks to the wonderful new team of DataBeersCPH organizers, including  Silvia de Sojo Caso, Jonas Juul, NERDS-member Sandro Sousa, and many more! Their hard work paid off – the location and vibe were absolutely amazing.

DataBeers is a global not-for-profit initiative (currently in 31+ cities), that brings data scientists and data enthusiasts from industry, government, academia and the arts to knowledge share. The DataBeers teams organise events and invite speakers to tell their experience with data: analysis, visualisations, applied data, data journalism etc., always in an informal and agile manner.

This last Copenhagen edition was sponsored by ITU and DTU. We are always happy about sponsors, especially for beer – talk to us at databeers.cph@gmail.com
The next DataBeers Copenhagen is scheduled for Spring 2023. Follow us at @databeers_cph for updates. Stay tuned, and cheers! 🍻

Social media updates: 1000 Twitter followers and Mastodon account

We have reached 1000 Twitter followers, around 3.5 years after having created our profile at: https://twitter.com/nerdsitu 🐦

To celebrate, we have also created a Mastodon account: https://mastodon.social/@nerdsitu 🐘 
For now we are cross-posting between Twitter and Mastodon (and aim to be reactive in both environments), so no matter where you follow us you will receive the same info and be able to stay in touch.

If you like our research, or are interested in our events, job opportunities, or news, make sure to follow us. Happy tweeting/tooting!  

Two new NERDS urban planning papers: COVID-19 vs. urban form and Micromobility network planning

We are on an urban planning streak, publishing two new papers in Environment and Planning B:

  1. Urban form and COVID-19 cases and deaths in Greater London: An urban morphometric approach, by A. Venerandi, L.M. Aiello, and S. Porta, published in Environment and Planning B

    The COVID-19 pandemic generated a considerable debate in relation to urban density. Many urban planners have advocated for rethinking our cities in ways that can decrease built-up density, in order to curb the spreading of future epidemics. In this work, we show that would be a bad idea. We used urban morphometrics to quantify built-up density in Greater London, and studied its relationship with COVID-19 cases and deaths at the level of MSOAs (small neighborhoods with an average population of ~8000). We found that urban density weakly and negatively correlates with both deaths and cases. The picture above (the low-density areas that some think could save us from contagion) shows the typical area in London with highest occurrence of COVID cases. The widespread belief that COVID cases scale with built-up density was supported mostly by city-level studies. The picture changes when comparing different areas within a city, which has been done for the first time in our study. The moral of the story is that built-up density is different from crowding. Let’s keep that in mind before worsening the urban sprawl of our cities. 
  2. Data-driven micromobility network planning for demand and safety, by P. Folco, L. Gauvin, M. Tizzoni, and M. Szell, published in Environment and Planning B

    In this paper we study how data of micromobility trips and crashes can shape and automatize infrastructure network planning processes. We introduce a parameter that tunes the focus between demand-based and safety-based development, and investigate systematically this tradeoff for the city of Turin. We find that a full focus on demand or safety generates different network extensions in the short term, with an optimal tradeoff in-between. In the long term, our framework improves overall network quality independent of short-term focus. Thus, we show how a data-driven process can provide urban planners with automated assistance for variable short-term scenario planning while maintaining the long-term goal of a sustainable, city-spanning micromobility network.
    See the interactive visualization: http://www.datainterfaces.org/projects/biketracks/#turin