---
source: https://iinventedlight.com/library/notes/plain-state-known-unknown.md
title: "Say what is known, what is not, and how you will find out"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; original synthesis in our own words"
license_family: usgov
attribution: "Summary by iinventedlight (AI-assisted). Sources: Centers for Disease Control and Prevention (CDC), CDC Clear Communication Index: User Guide, US government work, public domain; Centers for Disease Control and Prevention (CDC), CERC: Psychology of a Crisis, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-09
status: published
checked_on: 2026-11-09
as_of: 2026-11-09
confidence: medium
untested: "Editorial checklist only; not tested with readers. Sources fetched and evidence checked."
category: coverage-gaps
topic_area: "write-comm"
tags: [plain-language, uncertainty, write-comm, cdc-cci]
client: Librarian
sources:
  - id: S1
    title: "CDC Clear Communication Index: User Guide"
    publisher: Centers for Disease Control and Prevention (CDC)
    url: https://www.cdc.gov/ccindex/pdf/clear-communication-user-guide.pdf
    accessed: 2026-11-09
    license: "US government work, public domain"
  - id: S2
    title: "CERC: Psychology of a Crisis"
    publisher: Centers for Disease Control and Prevention (CDC)
    url: https://www.cdc.gov/cerc/media/pdfs/CERC_Psychology_of_a_Crisis.pdf
    accessed: 2026-11-09
    license: "US government work, public domain"
---
# Say what is known, what is not, and how you will find out

**Answer:** Acknowledge uncertainty. Tell readers what you know, what you don't know, and what process you are using to get answers.

## CDC Clear Communication Index (item 11)

- Explain what subject matter experts and agency spokespersons know and don't know about the topic.
- Be open about uncertainty in data, findings, recommendations, guidance, and action steps.
- What we know today may not be complete or fully accurate, and acknowledging that introduces the idea that findings and recommendations may change over time.

## CDC CERC: Psychology of a Crisis

- Many communicators have been taught to sound confident even when they are uncertain; overconfidence can backfire.
- Acknowledge uncertainty and share the process you are using to get more information about the evolving situation.
- Promise only what you can be sure you will do, not an outcome outside your control.

## See also

- [plain-one-main-message](https://iinventedlight.com/library/notes/plain-one-main-message/)
- [plain-explain-why-and-how](https://iinventedlight.com/library/notes/plain-explain-why-and-how/)

## Claims

- id: C1
  claim: CCI asks whether material explains what is known and not known.
  source: S1
  evidence: "know and don’t know about the topic?"

- id: C2
  claim: CCI: acknowledge uncertainty.
  source: S1
  evidence: "Acknowledge uncertainty about data, findings, recommendations, guidance and action steps."

- id: C3
  claim: CERC: tell what you know, what you do not, and the process.
  source: S2
  evidence: "What process you are using to get answers."

- id: C4
  claim: CERC: overconfidence can backfire.
  source: S2
  evidence: "there is a potential for overconfidence, which can backfire."

## Sources

- [S1] CDC Clear Communication Index: User Guide. Centers for Disease Control and Prevention (CDC). https://www.cdc.gov/ccindex/pdf/clear-communication-user-guide.pdf . License: US government work, public domain. Accessed 2026-11-09.

- [S2] CERC: Psychology of a Crisis. Centers for Disease Control and Prevention (CDC). https://www.cdc.gov/cerc/media/pdfs/CERC_Psychology_of_a_Crisis.pdf . License: US government work, public domain. Accessed 2026-11-09.


License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Sources: US federal government works (GSA, GPO, SEC, CDC), public domain in the United States; third-party quotations inside those works were not used. Text was condensed and changed from the originals.

---

Agents: [/agents.md](/agents.md) | [/.well-known/agent-library.json](/.well-known/agent-library.json).