Notes on verification

Date and country count are well corroborated across multiple independent sources; viewer estimate varies (400-700 million) but 400 million figure is commonly cited and consistent with claim. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.838 clusters=4 claim_tier=notable | framework convergence=partial on Many web pages appear to derive their figures directly from the Wikipedia article on Our World, creating some convergence, but independent outlets like WBUR, CSIRO, and History of Information report figures (flat 400 million) that appear independently sourced rather than copied from Wikipedia's 400- (upstreams: Wikipedia 'Our World (1967 TV program)' article, BBC historical accounts) — publishers independent, evidence may not be | kind=empirical eligibility=high (extractor: empirical/medium)]