Discovery ⏱ 2–3 hours 👥 2–4 CN practitioners. No client observers.
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Guides / How-to / The Corridor Mapping Session
How To — Discovery

The Corridor Mapping Session.

How to build the informal influence map with a small group

Purpose

To build the map of informal influence — who actually shapes what others think — that the formal stakeholder map cannot show. To identify the uncertain majority and who they will follow.

The CN approach
The corridor map is not a stakeholder map. A stakeholder map lists people by seniority and function. The corridor map identifies who actually influences decisions and whose informal opinion determines whether the uncertain majority adopt the change or resist it. It is built from interview data, observation and inference — not from the org chart. And it is used to design the engagement programme, not to report back to the sponsor.
Quick Reference — One Pager
Before you start
  • ▸Complete at least 8–10 discovery interviews before attempting the corridor map
  • ▸Gather all interview notes, observation notes and any informal intelligence
  • ▸Book 2–3 hours with no interruptions — this cannot be rushed
  • ▸Bring physical materials: large paper or whiteboard, sticky notes, pens
  • ▸Do not involve the client — this map is a CN working document
Room / setup
  • ▸Large wall or whiteboard surface
  • ▸Sticky notes in multiple colours: one colour per team/function
  • ▸Red pen for resistance indicators, green for support
  • ▸Space to stand back and look at the whole picture
Key questions

"Whose opinion does [name] defer to when the room goes quiet?"

"Who gave us the most names when we asked who we should talk to?"

"Who in this organisation would people follow into resistance — and who into adoption?"

"Where is the uncertain majority, and what will tip them?"

"Who are we most worried about — and why?"

Watch outs
⚠Conflating formal seniority with informal influence — they are rarely the same
⚠Missing the influential dissenter who is two levels below the sponsor
⚠Building the map from interviews with supporters only
⚠Treating the map as finished — it must be updated throughout the programme
⚠Showing the map in full to the client — it is a working tool, not a deliverable
Full Facilitator Guide in the CN Portal

Step by step. What to do when it goes wrong.

The full guide covers the complete session methodology, how to build and sequence the activities, what the outputs mean and how to use them, and specifically what to do when the session goes in a direction you did not expect.

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