{"id":2069,"slug":"van-der-bles-2020-pnas-uncertainty-numbers-safe","title":"van der Bles et al. 2020 PNAS — numeric uncertainty ranges do NOT damage trust in the source","kind":"reference","scope":"business","status":"current","audiences":["kevin","candid-team"],"topics":["uncertainty-communication"],"reference_body":"**Claim:** van der Bles et al. (2020, *PNAS* 117(14):7672-7683) ran four online experiments plus one field experiment on the BBC News website (total N≈5,780 UK adults). Per the authors' summary: numerically expressing uncertainty **\"causes people to be less confident in the number itself... but does NOT cause people to lose trust in the source of that number.\"**\n\n**Source:** van der Bles, Linden, Freeman, Spiegelhalter 2020, PNAS. Peer-reviewed; pre-registered.\n\n**Confidence:** Verified.\n\n**Why this matters for Candid:** Defines the safety of \"Based on your answers, your situation is High difficulty\" — confident at the source level even when the underlying inputs carry uncertainty. The widget can show numeric ranges (and SHOULD where they exist) without damaging credibility.","rationale_body":null,"metadata":null,"links":{"outgoing":[],"incoming":[{"slug":"research-brief-smb-widget-presenting-tiers-june-2026","title":"Research brief: SMB widget presentation layer — tiered results without overclaiming (June 2026)","kind":"reference","scope":"business","link_type":"relates-to"},{"slug":"rule-replace-vague-hedging-with-conditional-framing","title":"Rule — Replace vague hedging with confident conditional framing","kind":"rule","scope":"business","link_type":"depends-on"}]},"created_at":"2026-06-23T19:16:03.392Z","updated_at":"2026-06-23T19:16:03.392Z"}