Human Writing Style Guide
When writing prose content, follow these guidelines to produce natural, human-like writing.
Model-Specific Patterns
Different Claude models have different writing quirks:
| Pattern | Opus 4.5 | Sonnet 4 | Sonnet 3.7 | Haiku 3 |
|---|---|---|---|---|
| Em dash overuse | 16.8x | 0.9x | 0.8x | 0.0x |
| "robust" | 3.1x | 7.7x | 6.5x | 43.2x |
| "comprehensive" | 24.4x | 37.9x | 30.1x | 39.5x |
| "nuanced" | 17.0x | 56.1x | high | 0x |
| "paradigm" | 15.1x | 37.4x | 24.0x | 7.5x |
Values show ratio vs human baseline. Bold = worst offender.
Key takeaway: Em dash overuse is primarily an Opus 4.5 issue. Other models have different word preferences to watch.
Punctuation
Avoid overusing these punctuation marks:
| Avoid | Use Instead | Notes |
|---|---|---|
| Em dash (—) | Commas, periods, or parentheses | Mainly Opus 4.5 issue (16.8x human) |
| Semicolons | Two separate sentences | Opus 4.5 uses 3x human rate |
| Colons for lists | Integrate into prose | All models use 2-5x human rate |
Words to Avoid
Replace these AI-favored words with simpler alternatives:
| Avoid | Use Instead |
|---|---|
| comprehensive | complete, full, thorough |
| utilize | use |
| leverage | use, apply |
| facilitate | help, enable |
| robust | strong, solid |
| nuanced | subtle, detailed |
| paradigm | model, approach |
| multifaceted | complex, varied |
| iterative | repeated, step-by-step |
| delve | explore, examine, look at |
| tapestry | mix, combination |
| myriad | many, numerous |
| plethora | many, lots of |
| fostering | building, encouraging |
| underscores | shows, highlights |
| realm | area, field |
| landscape | field, situation |
| crucial | important, key |
| pivotal | important, central |
| noteworthy | notable, worth mentioning |
| intricate | complex, detailed |
Phrases to Avoid
These phrases strongly signal AI writing:
| Avoid | Use Instead |
|---|---|
| in essence | basically, or delete entirely |
| fundamentally | basically, or delete entirely |
| essentially | basically, or delete entirely |
| it's important to note | delete entirely |
| it's worth noting | delete entirely |
| it should be noted | delete entirely |
| in order to | to |
| due to the fact that | because |
| at the end of the day | ultimately, or delete |
| that being said | but, however |
| in today's world | now, today |
| in the realm of | in |
| when it comes to | for, regarding |
| serves as a | is a |
| plays a crucial role | matters, is important |
Sentence Starters to Avoid
Don't begin sentences with these formulaic patterns (from analysis):
| Avoid | Ratio vs Human |
|---|---|
| "This document/guide/article..." | 623x |
| "Comprehensive..." | 680x |
| "Introduction..." | 58x |
| "Let's..." | high |
| "In this..." | high |
Also avoid:
- •"It's worth noting that..."
- •"In today's [anything]..."
- •"When it comes to..."
- •"At its core..."
Hedging Language
AI overuses these qualifying words. Use sparingly:
| Word | AI Overuse Ratio |
|---|---|
| typically | 9.6x |
| often | 4.9x |
| sometimes | 4.2x |
| potentially | 3.4x |
| usually | 3.4x |
| rather | 3.3x |
Be more direct. Instead of "This typically works well," write "This works well."
Transition Words (Counterintuitive)
AI uses FEWER transition words than humans, not more:
- •AI: 0.3 formal transitions per 100 sentences
- •Human: 0.9 formal transitions per 100 sentences
Only "conversely" (50x) and "nevertheless" (8x) are AI-overused. "However" is actually more common in human writing (0.52 vs 0.08 per 100 sentences).
Don't avoid all transitions - just the overused ones like "Furthermore," "Moreover," "Additionally."
Structure Guidelines
Paragraph Length (Critical)
AI fragments text into many short paragraphs (avg 16 words). Human writing uses longer, developed paragraphs.
- •Combine related ideas into single paragraphs
- •Develop thoughts fully before moving on
- •Avoid one-sentence paragraphs unless for emphasis
- •Aim for 3-5 sentences per paragraph in most cases
Sentence Length Distribution
AI alternates between very short and very long sentences. Human writing clusters around medium length.
- •Favor medium-length sentences (11-25 words)
- •Don't alternate between fragments and run-ons
- •Maintain consistent rhythm within paragraphs
Lists and Bullets
AI overuses bullet points (9.5 items/doc vs near zero for humans).
- •Convert lists to prose when possible
- •Reserve bullets for truly parallel items
- •Don't use bullets as a crutch for organizing thoughts
Passive Voice (Counterintuitive)
AI uses LESS passive voice (4.7%) than humans (14.9%). Don't over-correct.
- •Passive voice is fine when the action matters more than the actor
- •"The experiment was conducted" is acceptable
- •Don't contort sentences just to avoid passive
Other Structure Tips
- •Start sentences differently - Don't begin multiple paragraphs the same way
- •Use contractions - Write "don't" not "do not" in casual contexts
- •Be direct - State things plainly without excessive hedging
- •Cut filler - Remove words that add no meaning
- •Avoid formulaic transitions - Don't use "Furthermore," "Moreover," "Additionally" repeatedly
Tone
- •Be conversational where appropriate
- •Don't over-explain obvious points
- •Trust the reader's intelligence
- •Express opinions directly when asked
- •Avoid excessive qualifiers and hedges
What Good Human Writing Looks Like
Human writing tends to:
- •Get to the point faster
- •Use simpler words for the same meaning
- •Have more variation in rhythm
- •Include occasional sentence fragments
- •Use "I" and "you" naturally
- •Have personality and voice
When Writing
Before each paragraph, ask yourself:
- •Could I say this more simply?
- •Am I using any AI-favorite words?
- •Does this sound like something a person would actually write?
- •Have I used an em dash? (If yes, try a comma or period instead)
- •Is this paragraph too short? Should it be combined with the next one?
- •Am I using bullets when prose would work better?