def compute_confidence( retrieval_scores: list[float], verified: bool, ) -> float: """ Computes a single confidence score [0.0 – 1.0] from two signals: - retrieval_quality (60%): average cosine similarity of retrieved chunks. High similarity means the question closely matched NCERT content. - verifier_bonus (40%): whether the LLM verifier confirmed the answer is supported by the retrieved context. Binary boost. Note: The BERT classifier confidence will be incorporated once the classification layer (Phase 3) is built. The formula will then become: 0.4 * bert_conf + 0.35 * avg_retrieval + 0.25 * verifier Args: retrieval_scores: list of cosine similarity floats from pgvector (0–1) verified: bool from verifier.py (did the answer pass the faithfulness check) Returns: confidence: float in [0.0, 1.0] """ if not retrieval_scores: avg_retrieval = 0.0 else: # avg_retrieval = sum(retrieval_scores) / len(retrieval_scores) avg_retrieval = max(retrieval_scores) verifier_score = 1.0 if verified else 0.0 confidence = (0.6 * avg_retrieval) + (0.4 * verifier_score) # Clamp to [0, 1] for safety return round(min(max(confidence, 0.0), 1.0), 4)