What problem does it solve? Measuring LLM quality by intuition leads to unreliable deployments and undetected regressions. This Skill provides a systematic evaluation framework combining automated metrics, human evaluation rubrics, and adversarial testing so you can quantify model quality and catch failures before users do. ## Core Features & Use Cases - Automated Metrics: Compute exact match, F1, BLEU, ROUGE-L, and BERTScore against ground-truth test sets, plus LLM-as-judge scoring with GPT-4 for nuanced criteria like helpfulness. - Human Evaluation: Run pairwise A/B comparisons and Likert-scale ratings across accuracy, completeness, clarity, and conciseness dimensions. - Adversarial & Factuality Testing: Probe jailbreak resistance, hallucination rates on unanswerable questions, bias patterns, and claim-level factual verification. - Use Case: Before swapping GPT-3.5 for GPT-4 in a customer support bot, run a 500-example test set through the eval harness, compare category-level F1 scores, and use the regression detector to confirm no capability dropped more than 5%. ## Quick Start Build an evaluation harness for my customer support chatbot with a test set covering common queries, edge cases, and adversarial prompts, then report automated metrics and regression risks.