Question

Each subject was given a different protocol on each of the three nights, and the order of the protocols was varied among the subjects that so that one-third had each protocol each night. What factors were the researchers attempting to control for with this approach?

Short answer

Each night, a subject received a different treatment. The researchers rotated the sequence of the procedures so that one-third of the subjects received a procedure every night.

The research was intended to decrease biases caused by treatment sequence or differences in the night environment.

Step-by-step solution

About the experiment

Twenty participants took part in the study, which aimed to establish the amount of ACTH in the human body during spontaneous and forced awaking procedures. Blood samples were tested in the laboratory to detect the level of ACTH.

ACTH (adrenocorticotropic hormone)

The pituitary gland, a tiny gland located near the base of the brain, synthesizes ACTH. Another hormone, cortisol, is regulated by ACTH. Two small glands located above the kidneys, the adrenal glands, produce cortisol.

The hormone cortisol aids stress and illness.

Factors to control the approach

During the experiment, each person was approached for a separately controlled protocol. First, during the long protocol, the predicted waking time was 9 a.m., similar to the actual waking time.

In short protocol, the predicted waking call was 6 a.m., close to the actual waking hour.