Composite signal: does the page give answer engines BOTH machine-readable Q&A (FAQPage schema) AND human-readable Q&A structure (question-formatted headings)? A page with neither is meaningfully worse than one with just one missing.
Impact is importance multiplied by the confidence tier’s weight — SPECIFICATION 1.0, RESEARCH 0.7, EMERGING 0.3, EXPERIMENTAL 0.1. Two rules backed by the same class of evidence therefore always carry the same weight, which is what makes the score reproducible rather than hand-tuned.