The point is that it's not a useful metric on its own. For example, redirecting from /dev/null also achieves a zero hallucination rate. We want the hallucinati

The point is that it's not a useful metric on its own. For example, redirecting from /dev/null also achieves a zero hallucination rate. We want the hallucination rate to decrease while the overall answer rate of queries remains sufficiently high. For more specifics, look into ROC and AUC.