OCR GCSE Biology B · J257
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
Revise: Development of MedicinesIn a blind trial, the participant does not know whether they receive the medicine or a comparison treatment. In a double-blind trial, neither the participant nor the doctor assessing them knows the allocation while the trial is under way. Double blinding reduces the chance that expectations influence reported symptoms, care or assessment.