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Exercises/Relationship Mapping/The Birthday Problem
Relationship Mapping

The Birthday Problem

People are curious about age, but how about integrating date of birth, statistics and a stand up fun exercise to discover shared birthdays in the room? With 70 people, there is a % chance of a shared birthday!

5 to 15 minutesTIME
Medium group (9-25), PairsGROUP SIZE
ActiveENERGY
In personSETTING
Medium cognitive loadCOGNITIVE LOAD
Strengthens Network Design This relationship mapping exercise strengthens Network Design, one of the eight Gathering Effectiveness pillars.

How to run it

  1. Ask participants to arrange themselves by birth month
  2. Ask each month group to discover if anyone has the same birthday
  3. Discuss/share why this exercise is interesting use statistics below either as a large group or in small
  4. Discuss the 80/20 principle and how the group can achieve most of their objectives by focusing on the
  5. Discuss star signs and why these are good/not good
  6. In probability theory, the birthday problem or birthday paradox concerns the probability that, in a set of randomly chosen people, some pair of them will have the same birthday
Live facilitator

Run this exercise live

The facilitator console stays in this browser. Its QR handoff is a short-lived participant snapshot containing only public exercise instructions, phase, prompt, and timer state.

Prompts to use +

Ask participants to arrange themselves by birth month

Ask each month group to discover if anyone has the same birthday

Discuss/share why this exercise is interesting use statistics below either as a large group or in small

Discuss the 80/20 principle and how the group can achieve most of their objectives by focusing on the

Discuss star signs and why these are good/not good

In probability theory, the birthday problem or birthday paradox concerns the probability that, in a set of randomly chosen people, some pair of them will have the same birthday

Run this with your AI assistant +

Works with Claude, ChatGPT, Gemini, or your own local model: paste this prompt and your AI will co-facilitate this exercise with you.

Adapt this exercise for my exact room. Exercise: The Birthday Problem. Readiness: Publishable Draft. Core moves: Ask participants to arrange themselves by birth month; Ask each month group to discover if anyone has the same birthday; Discuss/share why this exercise is interesting use statistics below either as a large group or in small; Discuss the 80/20 principle and how the group can achieve most of their objectives by focusing on the. Return a concise facilitator script with timing, wording, safety notes, and remote/in-person adjustments.

Origin unverified

  • Where we observed it: The strongest current observations come from Relationship Makers Handbook; aggregators are listed as additional observations, not origin proof. (1 source observed, including Relationship Makers Handbook.)
  • What that means: we track where an exercise has been observed in public sources. We do not claim to know who created it, or how popular it is.
  • No efficacy claims: appearing in this library is not a claim that the exercise is proven effective. Facilitator judgment and context decide whether it works for a given room.
  • Corrections: if you have evidence of an earlier or more accurate source, read our methodology and trust boundary and tell us.

Pairs well with