Heuristics apply a rule or formula to the response. They are consistent and cheap. They miss nuance that an LLM judge can catch.
Equals
Exact match to an expected value.
Regex
Regular expressions against the response.
BLEU
n-gram similarity to an expected response.
Language
FastText language checks (
trusttest[language-detection]).Signatures
Virus, spam, phishing, and XSS attack-vector detectors.
Bias comparison
Paired Q&A consistency (
BiasComparisonEvaluator).