What is error detection?

Error detection is a concept in personal epistemology: You cannot fix what you cannot detect — invest in error detection mechanisms.

Example: You have been writing a weekly newsletter for three months. You suspect the quality is declining, but you are not sure — you have no systematic way to tell. You reread last week's issue and feel vaguely dissatisfied, but you cannot identify whether the problem is structure, argument quality, unclear sentences, or just your mood. So you change nothing. Compare this to a writer who runs every draft through three specific checks: a structural audit (does every section advance the thesis?), a clarity scan (can each paragraph be summarized in one sentence?), and an engagement metric (did any sentence make the reader want to stop?). The second writer detects specific errors — a section that wanders, a paragraph that resists summary, a dead stretch in paragraph four. Only after detection can correction begin. The first writer has the same errors but no detection mechanism, so correction never starts.

This concept is part of Phase 25 (Error Correction) in the How to Think curriculum, which builds the epistemic infrastructure for error correction.