The Structure of Bridging

Carter Blair, Jakob de Raaij, Ariel D. Procaccia, Maxon Rubin-Toles, Nisarg Shah, Michelle Si, Serena Lutong Wang

Abstract:

Influential deliberation platforms such as Polis and Remesh employ metrics for identifying bridging statements,
which are accepted by participants who otherwise hold opposing views. A shortcoming of these metrics,
however, is that they only account for inter-group connections in a fixed partition of the participants into
groups. We argue that better bridging metrics must account for a richer set of possible partitions. To reason
about such metrics, we develop a mathematical framework for bridging. We use it to identify two compelling
metrics, pairwise disagreement and 𝑝-mean bridging, which are supported by axiomatic characterizations.
Experiments on real data show that our metrics are stable, interpretable, and practical, even under the sparse
observations typical of deliberation platforms.