double-blind
UK[ˌdʌbəl ˈblaɪnd]US[ˌdʌbəl ˈblaɪnd]
adj
(of a test or trial) organized so that neither the participants nor the investigators know which participants are receiving the experimental treatment and which are receiving a placebo or control, in order to prevent bias.
Morpheme Breakdown
double
blind
double
twofold
blind
unable to see
Etymology
The term 'double-blind' is a modern scientific compound, first used in the mid-20th century to describe a rigorous experimental protocol. It combines the English word 'double', with roots in Latin duplus, to indicate a dual layer of concealment. This is fused with 'blind', a Germanic word meaning sightless, here used figuratively to denote a state of purposeful ignorance. The compound's logic is elegantly literal: both the subjects and the experimenters are "blinded" to the key experimental variable, thereby eliminating two major sources of subjective bias and ensuring objective results.
Analysis
Structure: double (twofold) + blind (unable to see)
- double: From Latin duplus (twofold, double). In this compound, it functions as a quantifier meaning "two" or "in two ways."
- blind: From Proto-Germanic blindaz (blind). In this compound, it functions metaphorically to mean "without knowledge" or "kept unaware."
Examples
The clinical study was conducted as a randomized, double-blind trial.
To ensure unbiased results, the drug's efficacy was tested using a double-blind method.
In a double-blind experiment, neither the participants nor the researchers know who is receiving the actual treatment.