Bridging Systems

Bridging Systems

Bridging systems increase mutual understanding and trust across divides, creating space for productive conflict, deliberation, or cooperation.


Our goal in this paper is to articulate a research and practice direction around bridging systems. You can read the full paper here, published with the Knight First Amendment Institute at Columbia University as part of its Algorithmic Amplification and Society project. The abstract is below.

Divisiveness appears to be increasing in much of the world, leading to concern about political violence and a decreasing capacity to collaboratively address large-scale societal challenges. In this working paper we aim to articulate an interdisciplinary research and practice area focused around what we call bridging systems: systems which increase mutual understanding and trust across divides, creating space for productive conflict, deliberation, or cooperation. We give examples of bridging systems across three domains: recommender systems on social media, software for conducting civic forums, and human-facilitated group deliberation. We argue that these examples can be more meaningfully understood as processes for attention-allocation (as opposed to “content distribution” or “amplification”), and develop a corresponding framework to explore similarities — and opportunities for bridging — across these seemingly disparate domains. We focus particularly on the potential of bridging-based ranking to bring the benefits of offline bridging into spaces which are already governed by algorithms. Throughout, we suggest research directions that could improve our capacity to incorporate bridging into a world increasingly mediated by algorithms and artificial intelligence.

You might also be interested in the earlier policy paper on bridging-based ranking.



Aviv Ovadya Aviv Ovadya is an affiliate at the Berkman Klein Center for Internet & Society at Harvard University (at the Institute for Rebooting Social Media), and a visiting scholar at the Leverhulme Centre for the Future of Intelligence at Cambridge University. This work began while he was a Technology and Public Purpose Fellow at the Harvard Kennedy School’s Belfer Center. He can be found at his website, as @metaviv on Twitter, on Mastodon, and via his newsletter.

Luke Thorburn is a researcher in the UKRI Centre for Doctoral Training in Safe and Trusted AI at King’s College London. He also co-authors the Understanding Recommenders project for the Center for Human-Compatible AI at the University of California, Berkeley and has worked with the newDemocracy Foundation on technology for convening deliberative mini-publics. He can be found at his website, as @LukeThorburn_ on Twitter, and on Mastodon.

Our work on bridging systems is conducted in partnership with the GETTING-Plurality Research Network housed within the Allen Lab for Democracy Renovation at Harvard University.

We are putting together a working group to expand the paper and the broader work, adding more open problems and deeper explorations across disciplines. Please complete this form if you would be interested in contributing, or just kept in the loop on further developments.

Contact us

Any enquiries related to this work should be directed to the authors, whose email addresses are listed in the preprint.


We thank Tim van Gelder and Colin Megill for sharing information and insights from their work on YourView and Polis, respectively, and members of the GETTING-Plurality Research Network at Harvard University ( for their ongoing feedback and support. We would additionally like to thank Danielle Allen, Natania Antler, Katy Glenn Bass, Priyanjana Bengani, Leisel Bogan, Joaquin Quiñonero Candela, Alan Chan, Austin Clyde, Joe Edelman, Thomas Gilbert, Sam Hinds, Ravi Iyer, Amritha Jayanti, Julia Kamin, Emillie v. de Keulenaar, Andrew Konya, David Krueger, Stephen Larrick, Jesse McCrosky, James Mickens, Arvind Narayanan, Kathy Pham, Maria Polukarov, Richard Reisman, Afsaneh Rigot, Bruce Schneier, Jonathan Stray, Ted Suzman, Carmine Ventre, Jessica Yu, Glen Weyl and Cathy Wu, among others, for helpful discussions and feedback. Any errors or limitations of this work remain those of the authors.

Aviv Ovadya was supported in part by a Technology and Public Purpose Fellowship at the Belfer Center for Science and International Affairs, Harvard Kennedy School. Luke Thorburn was supported by UK Research and Innovation \[grant number EP/S023356/1], in the UKRI Centre for Doctoral Training in Safe and Trusted Artificial Intelligence (, King's College London.


This website and its content is made available under the MIT License.


In academic contexts, please cite this work using a citation similar to the following.

Aviv Ovadya and Luke Thorburn, Bridging Systems: Open Problems for Countering Destructive Divisiveness Across Ranking, Recommenders and Governance, 23-11 Knight First Amend. Inst. (Oct. 26, 2023), [].

Here is the BibTeX entry.

  author = {Ovadya, Aviv and Thorburn, Luke},
  title = {Bridging Systems: Open Problems for Countering Destructive Divisiveness across Ranking, Recommenders, and Governance},
  institution = {Knight First Amendment Institute},
  year = {2023},  
  month = {10},
  url = {}