Biology Topic Practice

Placebos and Double-Blind Trials

To ensure a drug study is unbiased, scientists use placebos and double-blind techniques.

What is a "double-blind" trial?

What is Placebos and Double-Blind Trials?

"A double-blind study is one in which neither the participants nor the experimenters know who is receiving a particular treatment."

Question 1

Why might a placebo be used in a double-blind clinical trial?

Question 2

Choose the best explanation: why might a placebo be used in a double-blind clinical trial?

Question 3

Select why might a placebo be used in a double-blind clinical trial?

Eliminating Bias

A placebo is a "fake" drug that has no active effect.

In a blind trial, the patient doesn't know if they have the real drug.

In a double-blind trial, neither the doctor nor the patient knows.

Exam Tip

Double-blind trials prevent doctors from accidentally influencing the results with their expectations.

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