double-blind trial

science

Also known as: double-blind study

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Last updated

June 25, 2026

Quick Summary

A double-blind trial is an experimental procedure where neither the subjects nor the experimenters know which participants are in the test group and which are in the control group. This method is crucial in scientific research, particularly when testing new drugs or treatments.12

The purpose of a double-blind setup is to prevent bias. If participants or researchers knew who was receiving the actual treatment versus a placebo (an inert substance), their expectations could influence the results. By keeping everyone unaware, the study aims to ensure that observed effects are due to the treatment itself, not psychological factors. This rigorous approach helps establish the true efficacy and safety of interventions.21

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control group
In a double-blind study, neither the subject nor the researcher will know which treatment the subject is receiving. In many cases, a double-blind study is preferable to a single-blind study, since the researcher cannot inadvertently affect the results or their interpretation by treating a control subject differently…
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In a double-blind study, neither the subject nor the researcher will know which treatment the subject is receiving. In many cases, a double-blind study is preferable to a single-blind study, since the researcher cannot inadvertently affect the results or their interpretation by treating a control subject differently…
Read More

therapeutics
Designing a therapeutic regimen
Such a study is “double-blind”: it controls for both possible tendencies by comparing an active drug with an inactive placebo (an inert drug). Neither the patient nor the physician knows which drug the patient is taking, so that neither one’s bias can influence the result. Although this is the…
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Such a study is “double-blind”: it controls for both possible tendencies by comparing an active drug with an inactive placebo (an inert drug). Neither the patient nor the physician knows which drug the patient is taking, so that neither one’s bias can influence the result. Although this is the…
Read More

Henry Knowles Beecher
…to recognize the importance of double-blind placebo-controlled clinical trials (in which neither subject nor doctor know whether the subject will receive a drug or a placebo)..
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…to recognize the importance of double-blind placebo-controlled clinical trials (in which neither subject nor doctor know whether the subject will receive a drug or a placebo)..
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