Reference-Free Evaluation

Reference-free evaluation scores a model's output based solely on the input and the response itself, without requiring a gold-standard reference answer. This is valuable when ground truth is costly to produce or ambiguous — for example, evaluating an open-ended conversational response. LLM-as-judge approaches are inherently reference-free. The trade-off is that without a verified correct answer to anchor judgment, scores reflect perceived quality rather than factual correctness.