Graphite study finds model-specific writing 'tells' — Opus 5.5 overuses 'this matters'
Marketing firm Graphite analyzed rewrites of 10,000 pre-ChatGPT articles to compare human prose with outputs from frontier LLMs and found about 13,000 phrases that appear at least twice as often in AI-generated text. The report highlights model-specific habits — Anthropic's Opus 5.5 strongly overuses words like "dependable" and the phrase "this matters," while OpenAI's Astra favors hedges and "corrective framing," and many models have reduced em-dash usage.