A double-blind experiment is one in which the people kept unaware are:

1. Blinding or masking in a randomized experiment preserves the power of suggestion. 2. A single-blind design keeps only the subjects unaware of their group. 3. A double-blind experiment is one in which both the subjects and the researchers involved with the subjects are blinded. 4. That prevents researcher expectations leaking into the measurements. 5. The people analysing the data are a separate consideration again. _Source: OpenStax Introductory Statistics 2e (CC BY 4.0), Ch 1 'Sampling and Data', sections 1.1-1.4_