Four participants sign up for an experiment examining the effects of alcohol on sociability. one participant is given an alcoholic beverage to drink and is told that it is alcohol. a second participant is given an alcoholic beverage to drink but is told that it is nonalcoholic. a third participant drinks a nonalcoholic beverage but is told that it contains alcohol, and a fourth participant is given a nonalcoholic beverage and is told that it is nonalcoholic. this illustrates a placebo design.

Balanced placebo design.

Explanation:

A balanced placebo design is a type of experimental research design where there are four conditions of treatment – as described in the text above. In this type of design, both drugs and placebo are tested at the same time to check whether the drug is actually affecting the participants as it is intended to. The conditions as described in the text to be experienced by the second and third participant will help the researchers determine the drug’s efficacy.

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explanation:

agreeableness is a personality trait manifesting itself in individual behavioral characteristics that are perceived as kind, sympathetic, cooperative, warm, and considerate.

fir trees are found in areas with cooler climates. fir trees have needles for leaves and remain green year-round.