Week 5: Presence at Scale

Crossing 3's lecture — what a team changes about a Crossing, how to build something that still works when all five of you walk away, and what the Showcase account has to answer

24 August 2026

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One presenter this fortnight rather than the usual two: George Curious is both the convenor and Crossing 3’s tutor, so the handover in the middle is just a change of register. Same shape as every other week — the idea first, then how to actually do it.

The first half — why a team changes the question

Crossings 1 and 2 both worked because you were standing there starting them. Crossing 3 assigns you four other people and asks for something that doesn’t depend on that, which is a different problem rather than a larger version of the same one.

The evidence half starts with Ringelmann, who hooked a rope to a pressure gauge and had people pull: add pullers and the total climbs, but each person’s share of it falls. Latané, Williams and Harkins ran the same shape of experiment with clapping and shouting and separated the two reasons a group underperforms — some of the loss is bad coordination, and some of it is simply effort. The second kind is the one you can do something about, because it shrinks when each person’s output is measurable. It was never laziness, it was being un-measurable. So the accountability has to come from inside the team: distinct jobs, named out loud, before the table goes up.

The half closes on the test the whole Crossing turns on. If the thing stops being a thing the moment nobody is standing next to it, you built a conversation with extra steps.

The second half — how to actually run one

Whyte’s word for what makes a stranger stop is triangulation: some external stimulus that prompts strangers to talk to strangers as if they knew each other. His example, via Project for Public Spaces, is a bench, a bin and a phone — scattered, each gets very little use; put together with a coffee cart, people arrive. Nobody stops to talk to a table. They stop for the thing on it, and Set Up Shop asks your stall to be that thing — including across the lunch break, when it is one of you holding the table rather than five.

Then the telling, which is where the Crossing is actually won. Week 6 is one slot per team in a fuller room — the Hallway Showcase — and the shape of the account is the army’s after-action review, more or less: what was supposed to happen, what actually happened, why there was a difference, what you’ve learned. Most teams arrive able to do the first. Almost nobody arrives with the third. Running those four questions against the stall you’re planning is the most useful hour of the fortnight, which is why the framework is in week 5 and not week 6.

It ends on the one failure mode George can always spot: an account assembled for a bigger audience, rather than the one you were giving each other while it was still going wrong.

What you should leave knowing

Teaching team