I'm not sure the actual ChatGPT chat interface is capable of measuring perplexity/burstiness yet (unless OpenAI integrated their recent detection work into the actual ChatGPT model which I don't think is the case).
A document's perplexity is a measurement of the randomness of the text
Burstiness Score: 1089.841
A document's burstiness is a measurement of the variation in perplexity
Its conclusion was "Your text is most likely human written but there are some sentences with low perplexities". There was only one sentence highlighted as possibly written by AI: "However, each tool has its pros and cons."
It's also possible to prompt ChatGPT to write with high perplexity and burstiness, so also decent chance of false negatives.
Per GPTZero on the first few thousand characters https://gptzero.me/:
Average Perplexity Score: 632.205
A document's perplexity is a measurement of the randomness of the text
Burstiness Score: 1089.841
A document's burstiness is a measurement of the variation in perplexity
Its conclusion was "Your text is most likely human written but there are some sentences with low perplexities". There was only one sentence highlighted as possibly written by AI: "However, each tool has its pros and cons."
It's also possible to prompt ChatGPT to write with high perplexity and burstiness, so also decent chance of false negatives.