Welcome Jacob to NERDS!

Meet the newest member of NERDS – Jacob Aarup Dalsgaard! Jacob is a PhD student in social data science at SODAS – our KU sister group, and will be a visiting PhD student at ITU. Jacob will be diving deep into the world of bias in science, focusing especially on algorithms and models, as part of the BiasExplained project funded by the Villum Foundation. We’re super happy to have him on board and can’t wait to see all the contribution he will bring to the group. 💡

Welcome to the NERDS squad, Jacob! 🖖

Another smashing DataBeers Copenhagen, with 170 participants

Four years after we brought DataBeers to Denmark, another successful event was held this week in Copenhagen!

DataBeers is a global not-for-profit initiative active in dozens of cities worldwide, 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 week’s event was again co-organized by NERDS (especially Sandro and Arianna), and also featured Michael as one of the speakers with a magic-themed talk on “Stories from 1001 paths (over Dybbølsbro)” – slides available here [pdf]: http://michael.szell.net/downloads/talk_szell2023sfp.pdf

The event had a fantastic vibe, great speakers, and a psyched audience including many ITU students. Apart from the four speakers from academia and industry, it also featured a scientific presentation karaoke. Here some visual impressions from the event, which this time took place in Absalon, a locally famous church-turned-into-community-center:

DataBeersCPH has now grown to accommodate 170 participants, with the event’s free tickets having become sold out one week before the event, mainly through word-of-mouth. The event’s free beers and its venue were charitably sponsored by the DDSA, DTU, ITU, and KU.

Here’s two cheers for many more successful DataBeers in Copenhagen to spread our love for data and science (and beers)! 🍻 🍻

New NERDS review paper on Sidewalk Networks

Sidewalk networks: Review and outlook, by D. Rhoads, C. Rames, A. Solé-Ribalta, M.C. González, M. Szell & J. Borge-Holthoefer, published in Computers, Environment and Urban Systems

From a transport perspective, increasing active travel –and walking in particular– is crucial for the future of sustainable cities, as reflected in global decarbonisation policies and agendas. Further, walking is much more than a mere mode of transport: it provides a fundamental social function, fostering vibrant cohesive communities. Arguably, walking and its associated infrastructure –sidewalks– should rank among the highest priorities for planning authorities. However, efficiency- and speed-driven urbanisation has gradually reallocated street space to private cars, leading to automobiles being the prioritised mode of transport today. Empirical research has generally followed suit, and a systemic understanding of walking as a phenomenon is largely missing, i.e., questions like how connected, resilient, accessible, or socially equitable is the pedestrian infrastructure of whole neighbourhoods and cities. Such relative neglect of sidewalk network research is, first and foremost, the consequence of a generalised lack of publicly available data on sidewalk infrastructure worldwide. A second reason might be its apparent lack of interest from a systemic standpoint: pedestrian mobility does not produce coordination challenges on the scale that cars do. In this work, we confront this perception by showing that there is ample research potential in the study of system-wide sidewalk networks, with both structural and dynamical challenges which might be critical to pursue the latest aspirations towards sustainable mobility in cities.

OECD recommendations for mobility policies based on NERDS research

The OECD/ITF (International Transport Forum) released the document “Towards the Light: Effective Light Mobility Policies in Cities” with policy recommendations towards more sustainable cities through light mobility such as bicycles, scooters, or micro vehicles.


In this report, a whole section called “Go faster! Develop high-quality wheeled light mobility infrastructure that fits the context” is based almost entirely on several of our NERDS papers on bicycle/micromobility network analysis. The section discusses how “a strong effort should be made to ensure that the newly created network is connected to the greatest extent possible and allows access to important and popular points of interest”, and how data-driven approaches that we developed are “important tools” that can complement traditional manual approaches:

Further, the report cites a previous study of ours on the perceived distribution of road space,

[Cars] have become so entrenched in the urban landscape that the general public often systematically overestimates the amount of mobility space allocated to non-motorised modes – while underestimating the space allocated to the car (Szell, 2018). Additionally, much of the violence they impose on all other road users is normalised and remains unaddressed in public and policy discourses.

and concludes:

Policy makers and planners need to remove their car blinders and cure their car blindness so that they can finally see the light.

We wholeheartedly agree and are happy that our research is useful for sustainable policy-making in an international context. (The International Transport Forum is an inter-governmental organisation within the OECD system, and is the only global body with a mandate for all modes of transport. It acts as a think tank for transport policy issues and organises the annual global summit of transport ministers.)

Assoc Prof wanted!

ITU is looking for an Associate Professor in data science and machine learning, including network science, computational social science: Read more and apply at the official call page
Deadline: Sep 8

This is not a call specific to any research group at ITU, but if the new Assoc. Prof’s topic fits with our group NEtwoRks, Data, and Society (NERDS) at IT University of Copenhagen, they could join us. NERDS focuses on quantitative projects at the boundary of computational social science and network science, including science of science, social dynamics, urban sustainability, data visualization, and fundamental questions in complex systems.

Both salary and working conditions are excellent at ITU. NERDS is a down-to-earth and fun place to be, we have won the Research Environment of 2022 prize. Copenhagen is often named as the best city in the world to live in, and for good reasons. It’s world-renowned for food, beer, art, music, architecture, the Scandinavian “hygge”, and much more. In Denmark, parental leave is generous, and child-care is excellent and cheap.

If you are interested to know more about NERDS or working at ITU please reach out to us.

New NERDS paper: Mobility science

Future directions in human mobility science, by L. Pappalardo, E. Manley, V. Sekara, L. Alessandretti, published in Nature Computational Science


We provide a brief review of human mobility science and present three key areas where we expect to see substantial advancements. We start from the mind and discuss the need to better understand how spatial cognition shapes mobility patterns. We then move to societies and argue the importance of better understanding new forms of transportation. We conclude by discussing how algorithms shape mobility behavior and provide useful tools for modelers. Finally, we discuss how progress on these research directions may help us address some of the challenges our society faces today.

Roundup of NERDS at IC2S2

This year’s IC2S2, the 9th International Conference on Computational Social Science is now over, and it was a smashing success! The conference brought together over 700 people from dozens of countries, doubling in size compared to the previous edition. With 50% PhD and 30% Postdoc participants, the Computational Social Science community is young and refreshingly open, which could also be seen from the diversity of keynote speakers, spanning from evolutionary biologists to tourism/transport researchers. This community is the opposite of calcified – rather, it brought together experts and ideas from different fields for a true, unpolitical exchange and cross-pollination. This is how science should be done.

We fully echo the sentiments of the president of the new International Society for Computational Social Science (ISCSS), Duncan Watts, who concluded in the IC2S2 town hall meeting: We don’t have clear boundaries. Whoever identifies as computational social scientist should come to IC2S2.

NERDS played a significant role at IC2S2. We co-organized the conference, chaired several sessions, held a successful tutorial, and gave 2 lightning talks, 7 parallel talks, and presented 13 posters. See the full list of our activities here: NERDSIC2S2.PDF

Finally, let us share our visual impressions of NERDS@IC2S2:

See you next year at IC2S2 2024 in Philadelphia!

Catch us at IC2S2!

Besides co-organizing the conference and chairing several sessions, NERDS are omnipresent with events and activities at this year’s IC2S2, the 9th International Conference on Computational Social Science. In fact, we will give 2 lightning talks, 7 parallel talks, and present 13 posters, apart from having organized today’s successful tutorial on Geospatial Data Science:

See here a full list where you can catch us for the rest of the week: NERDSIC2S2.PDF

Enjoy Copenhagen and IC2S2!

Welcome Anders to NERDS!

Anders Giovanni Møller graduation at ITU

NERDS welcomes a new member: Anders Giovanni Møller. Starting today, Anders will be a PhD student working with Luca Aiello on the COCOONS project at the intersection between NLP and complex systems. Anders can boast a long tenure at ITU, and last week he got his Master’s degree in Data Science. He was selected for a keynote address to the whole 2023 cohort of ITU MSc graduates during the graduation ceremony — a very moving and inspiring speech! Welcome, Anders!

New NERDS summer papers: BikeDNA, Climate change ads, Social sleep

We welcome the summer with 3 new diverse papers!

  1. BikeDNA: A tool for bicycle infrastructure data and network assessment, by A. Rahbek Vierø, A. Vybornova & M. Szell, published in Environment and Planning B

    See also: https://github.com/anerv/BikeDNA
    Building high-quality bicycle networks requires knowledge of existing bicycle infrastructure. However, bicycle network data from governmental agencies or crowdsourced projects like OpenStreetMap often suffer from unknown, heterogeneous, or low quality, which hampers the green transition of human mobility. In particular, bicycle-specific data have peculiarities that require a tailor-made, reproducible quality assessment pipeline: For example, bicycle networks are much more fragmented than road networks, or are mapped with inconsistent data models. To fill this gap, we introduce BikeDNA, an open-source tool for reproducible quality assessment tailored to bicycle infrastructure data with a focus on network structure and connectivity. BikeDNA performs either a standalone analysis of one data set or a comparative analysis between OpenStreetMap and a reference data set, including feature matching. Data quality metrics are considered both globally for the entire study area and locally on grid cell level, thus exposing spatial variation in data quality. Interactive maps and HTML/PDF reports are generated to facilitate the visual exploration and communication of results. BikeDNA supports quality assessments of bicycle infrastructure data for a wide range of applications—from urban planning to OpenStreetMap data improvement or network research for sustainable mobility.
  2. How Do US Congress Members Advertise Climate Change: An Analysis of Ads Run on Meta’s Platforms, by L. Aisenpreis, G. Gyrst & V. Sekaram published in Proceedings of the International AAAI Conference on Web and Social Media

    Ensuring transparency and integrity in political communication on climate change has arguably never been more important than today. Yet we know little about how politicians focus on, talk about, and portray climate change on social media. Here we study it from the perspective of political advertisement. We use Meta’s Ad Library to collect 602,546 ads that have been issued by US Congress members since mid-2018. Out of those only 19,176 (3.2%) are climate-related. Analyzing this data, we find that Democrats focus substantially more on climate change than Republicans, with 99.7% of all climate-related ads stemming from Democratic politicians. In particular, we find this is driven by a small core of Democratic politicians, where 72% of all impressions can be attributed to 10 politicians. Interestingly, we find a significant difference in the average amount of impressions generated per dollar spent between the two parties. Republicans generate on average 188% more impressions with their climate ads for the same money spent as Democrats. We build models to explain the differences and find that demographic factors only partially explain the variance. Our results demonstrate differences of climate-related advertisements of US congress members and reveal differences in advertising characteristics between the two political parties. We anticipate our work to be a starting point for further studies about climate-related ads on Meta’s platforms.
  3. Social dimensions impact individual sleep quantity and quality, by S. Park, A. Zhunis, M. Constantinides, L.M. Aiello, D. Quercia & M. Cha, published in Scientific Reports

    While sleep positively impacts well-being, health, and productivity, the effects of societal factors on sleep remain underexplored. Here we analyze the sleep of 30,082 individuals across 11 countries using 52 million activity records from wearable devices. Our data are consistent with past studies of gender and age-associated sleep characteristics. However, our analysis of wearable device data uncovers differences in recorded vs. self-reported bedtime and sleep duration. The dataset allowed us to study how country-specific metrics such as GDP and cultural indices relate to sleep in groups and individuals. Our analysis indicates that diverse sleep metrics can be represented by two dimensions: sleep quantity and quality. We find that 55% of the variation in sleep quality, and 63% in sleep quantity, are explained by societal factors. Within a societal boundary, individual sleep experience was modified by factors like exercise. Increased exercise or daily steps were associated with better sleep quality (for example, faster sleep onset and less time awake in bed), especially in countries like the U.S. and Finland. Understanding how social norms relate to sleep will help create strategies and policies that enhance the positive impacts of sleep on health, such as productivity and well-being.