If you had to classify AI-assisted writing into categories, how would you do it?

I’m building a research framework around AI-assisted writing workflows, and I’m realizing very quickly that most existing labels (“AI-generated,” “human-written,” etc.) completely break down once you look at how people actually write.

For example:

• Someone writes everything themselves with no AI involvement
• Someone uses AI only for brainstorming or outlining
• Someone has AI generate placeholder text but rewrites the final wording entirely
• Someone edits AI-generated passages into their own prose
• Someone mostly uses AI output with light human editing

At some point these become meaningfully different processes — but the boundaries are extremely unclear.

Right now I’m experimenting with four broad categories:

1. Human-written (no LLM involvement)
2. Human-written with AI-assisted process (e.g., AI generates placeholder text, human rewrites completely)
3. Mixed authorship
4. Primarily AI-generated

But I’m not convinced these categories are robust enough yet.

If you had to build a classification system for modern writing workflows, how would you structure it?

Where do these categories fail?
What edge cases break them?
What distinctions actually matter to you, if any? What do you think will matter to others?

The target audience are those who think critically about AI's impact on writing, art, and broader human capability.