Final answer:
Dr. Adriana's use of random assignment in her soccer uniform study is crucial for ensuring each player had an equal chance of wearing either uniform, reducing bias and allowing for a fair comparison of performance outcomes.
Step-by-step explanation:
Dr. Adriana conducted a study to determine if players who wear a new type of soccer uniform made from a specially designed fabric will perform better in soccer matches. It was important for Dr. Adriana to randomly assign the players to wear new or old uniforms because she wanted to ensure that each player had an equal chance of wearing the new or old uniform.
Random assignment reduces bias and increases the likelihood that the two groups are equivalent at the start of the experiment, which is essential for the validity of the results. This method helps ascertain that the observed effects on performance are due to the uniforms being tested and not confounded by other factors, such as certain players always being on the same team or having the same abilities.