a-researcher-finds-a-correlation-between-smartphone-usage-and-sleep-quality-what

Question

A researcher finds a correlation between smartphone usage and sleep quality. What should be considered before concluding that smartphone usage affects sleep quality?

Accepted Answer

Other factors such as stress and lifestyle should be considered.

Answer

There is no need to consider other factors.

Answer

Smartphone usage directly affects sleep quality.

Answer

Sleep quality affects smartphone usage.