Question

a company wants to study the effectiveness of a new pain relief medicine. they recruit 100 volunteers who suffer chronic pain.

half of the 50 males are randomly assigned to the treatment group, and the other half are assigned to the control group. the same method is used to randomly assign half of the 50 females to the treatment group and the other half to the control group.

what type of experiment design is this?

choose 1 answer:
a completely randomized
b systematic
c stratified
d randomized block

Explanation:

1. Understand Experiment Designs:

• Completely Randomized: Subjects are randomly assigned to treatment/control without blocking.
• Systematic: Subjects are selected with a fixed interval, not relevant here.
• Stratified: Population is divided into strata, and samples are taken from each stratum (used in sampling, not experimental assignment).
• Randomized Block: Subjects are divided into blocks (homogeneous groups), then randomly assigned within each block.

1. Analyze the Problem:

• Volunteers are divided into blocks (males and females, which are homogeneous in gender).
• Within each block (males, females), subjects are randomly assigned to treatment/control.
• This matches the definition of a randomized block design, where blocks are formed (gender here) and random assignment occurs within each block.

Answer:

D. Randomized block