Direct answer
Retest a fixed set of target-market questions across platforms and rounds. Track brand mention rates, official-site and evidence citation rates, factual accuracy, supplier shortlist rates, competitor co-occurrence, and inquiry signals. Save the platform, model, region, language, mode, full answer, and final source URLs for each test. One answer is not a stable result.
Scope and limitations
Results vary across platforms and models, and crawling and indexing take time. Reports should show sample sizes, invalid answers, control groups, and retest dates, not just an overall percentage with no measurement definition.