Question

In an interesting experiment, researchers examined the effect of ultrasound on birth weight. Pregnant women participating in the study were randomly assigned to one of two groups. The first group of women received an ultrasound; the second group did not. When the subjects’ babies were born, their birth weights were recorded. The women who received the ultrasounds had heavier babies.

Based on your answers to Questions $1$ and $2$, describe an improved design for this experiment

Short answer

It would have produced unbiased results.

Step-by-step solution

Given information

Pregnant women participating in the study were randomly assigned to one of two groups.

Concept

A placebo is an inactive treatment, sometimes called a 'sugar pill.

In a double-blind experiment, neither the subjects nor the people who interact with them and assess the response variable are aware of the treatment they received.

Explanation

Based on the facts provided, it is determined that the Placebo and double-blind studies should be considered. It would have yielded objective results.