British researchers randomly assigned 424 hospitalized premature infants either to formula feeding or to breast-milk feeding.They found that on intelligence tests taken at the age of 8,those who were breast fed significantly scored higher than those who were formula fed.These researchers conducted a(n):
A) survey.
B) naturalistic observation.
C) experiment.
D) correlational design.

Question

Quizplus · Accepted Answer

This study involved assigning participants to different groups (breast-fed or formula-fed) and measuring the outcome (intelligence scores). This is a classic experimental design, with random assignment being a crucial feature of experimental research.

British Researchers Randomly Assigned 424 Hospitalized Premature Infants Either to Formula