# Plain language: sentences average <20 words, jargon avoided, active voice >50%

- **Pattern:** `ab-001617` (`gov-web-standards.plain-language.readability-metrics`)
- **Severity:** high
- **Lifecycle:** active
- **Last modified:** 2026-04-18
- **Canonical URL:** https://auditbuffet.com/patterns/ab-001617
- **License:** CC-BY-4.0 — attribute to AuditBuffet Pattern Catalog (https://auditbuffet.com/patterns/ab-001617)

## Why it matters

The Plain Writing Act of 2010 mandates that federal agencies use plain language in all public-facing documents and websites. Long, passive-voice sentences and unexplained jargon raise the cognitive load for all readers and functionally exclude people with lower literacy levels, non-native English speakers, and users accessing services under stress. When the average sentence exceeds 25 words, comprehension drops sharply for the majority of the U.S. adult population. Non-compliance with the Federal Plain Language Guidelines also signals systemic content governance failure — content that was never reviewed before publication.

## Severity rationale

High because content that violates the Plain Writing Act of 2010 and Federal Plain Language Guidelines actively prevents large segments of the public — including non-native English speakers and lower-literacy users — from understanding and using government services they are legally entitled to access.

## Remediation

Audit content on at least three public pages (home, about, a service page) using the plainlanguage.gov checklist. Target average sentence length under 20 words, active voice above 50%, and zero unexplained acronyms.

Revise sentences using this pattern:
```
// Before (passive, 22 words):
"The aforementioned documentation must be submitted in accordance with the
regulations established by the department."

// After (active, 10 words):
"Submit your documents following the department's rules."
```

For acronyms, expand on first use: "Freedom of Information Act (FOIA)." Use the Hemingway Editor or `write-good` linter in CI to flag readability regressions before deployment.

## Detection

- **ID:** `readability-metrics`
- **Severity:** `high`
- **What to look for:** Read page content (About, Contact, home page intro, any policy pages) and manually assess. Count every sentence on at least 3 pages and compute: (1) average word count per sentence, (2) jargon density (unexplained technical terms per 100 words), (3) active voice ratio. For each page, enumerate all unexplained acronyms and jargon terms found.
  - Sentence length: Count words in sample sentences; aim for average <20 words.
  - Jargon: Look for unexplained technical terms, acronyms without definitions, or legal language.
  - Active voice: Sample at least 10 sentences; count how many use active voice (subject performs action) vs. passive voice (subject is acted upon).
- **Pass criteria:** Sample content shows average sentence length under 20 words, no more than 2 unexplained jargon terms per page, and over 50% of sentences use active voice. Report the ratio of active-voice sentences even on pass (e.g., "8 of 10 sampled sentences use active voice").
- **Fail criteria:** Sample content has average sentence length over 25 words, more than 2 unexplained jargon terms per page, or fewer than 50% active voice usage. Defining acronyms in a glossary page but not on the page where they appear does not count as pass.
- **Skip (N/A) when:** The site has no public-facing text content (API-only or documentation sites may skip).
- **Cross-reference:** For deeper content quality assessment including reading level scoring, the Content Quality audit evaluates readability metrics using Flesch-Kincaid and automated scanning.
- **Detail on fail:** `"Average sentence length on home page is 28 words; target is <20. Sentences like 'The aforementioned regulations necessitate the provision of requisite documentation...' use passive voice and jargon."` or `"Acronyms (FOIA, 21 CFR) appear without explanation"`
- **Remediation:** Rewrite content using the Plain Language principles (plainlanguage.gov):
  - Use short sentences (10–20 words average)
  - Define acronyms on first use: "Freedom of Information Act (FOIA)"
  - Use active voice: "We collect feedback" instead of "Feedback is collected"
  - Avoid jargon; use common words: "use" instead of "utilize", "help" instead of "facilitate"

  Example revision:
  ```
  Before: "The aforementioned regulations necessitate compliance with established guidelines."
  After: "You must follow these rules."
  ```

## External references

- external plain-writing-act-2010 — https://www.congress.gov/111/plaws/publ274/PLAW-111publ274.pdf
- external federal-plain-language-guidelines — https://www.plainlanguage.gov/guidelines/

Taxons: content-integrity, regulatory-conformance

HTML version: https://auditbuffet.com/patterns/ab-001617