How AI Detection Actually Works Under the Hood

AI content detection has become a billion-dollar industry, but few people understand how these tools actually work.

At their core, AI detectors are classifiers trained to distinguish between human and AI-generated text. The two most important metrics are perplexity and burstiness.

Perplexity measures how "surprised" a language model is by a piece of text. Human writing tends to have higher perplexity.

Burstiness measures the variation in sentence complexity. Humans naturally write with high burstiness.

The limitations are real. All detectors have false positive rates. Non-native English speakers are disproportionately affected.

Understanding these mechanics is key to effective humanization. By increasing perplexity and burstiness, tools like WriteHumane shift AI text into the range detectors classify as human.