Definition

1. Noun:
   • A scientific experimental method: A "double-blind procedure" is a specific type of experimental design used in research, particularly in fields like medicine and psychology.
   • Key characteristic of concealment: In this procedure, two key groups of people are deliberately kept unaware of ("blind to") certain critical information. Neither the participants (subjects) in the experiment nor the researchers who directly interact with them and administer the treatments know which participants are receiving the actual treatment and which are receiving a placebo or control intervention.

Usage

• The "double-blind procedure" is used to ensure the objectivity and validity of experimental results.
• It is a standard method for testing the efficacy of new drugs, medical treatments, or psychological interventions.
• The purpose is to prevent bias. If the participants knew what they were receiving, their expectations could influence the results (placebo effect). If the experimenters knew, they might unconsciously influence the participants or interpret data in a biased way (experimenter bias).

Examples

• Noun:
  • The clinical trial for the new vaccine followed a double-blind procedure to ensure unbiased results.
  • To test the new cognitive therapy, researchers employed a double-blind procedure where neither the patients nor the therapists knew who was in the treatment group.

Advanced Usage

• "to employ/use a double-blind procedure": This is the standard phrasing for implementing this method in research.
  • The study's credibility was strengthened because it used a double-blind procedure.
• "conducted under double-blind conditions": Describes the environment of the experiment.
  • All experiments were conducted under double-blind conditions.

Variants and Related Words

• Double-blind study (n): A complete research project that uses the double-blind procedure. Often used interchangeably.
  • The findings from the double-blind study were published in a major journal.
• Double-blind experiment (n): Essentially synonymous with "double-blind procedure," emphasizing the experimental aspect.
  • It was a carefully controlled double-blind experiment.
• Single-blind procedure (n): An experimental design where only the participants are unaware of their group assignment, but the researchers are not.
• Blinding (n): The general act of concealing information in an experiment to prevent bias.

Synonyms

• Double-blind study: A research study using this method.
• Double-blind trial: Commonly used in the context of clinical trials for drugs or medical treatments.
• Double-blind design: Emphasizes the structural plan of the experiment.

Related Terms (Not Phrasal Verbs)

• Placebo control: A dummy treatment given to the control group, often used in conjunction with a double-blind procedure.
• Randomization: The process of randomly assigning participants to different groups (e.g., treatment or placebo), which is a key component used alongside a double-blind procedure.
• Control group: The group in an experiment that does not receive the active treatment, used for comparison.

Noun

1. an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment
   • a double-blind procedure is used to guard against both experimenter bias and placebo effects