What happens if an experiment tests more than one factor at the same time?

What happens if an experiment tests more than one factor at the same time?

• A. It may speed up the discovery of causes.
• B. It reduces the amount of data needed.
• C. It may lead to confusion about which factor influenced the results.
• D. It leads to faster conclusions.

Answer: (C)

When more than one factor is varied at once, the observed outcome can result from any one factor, or from their interaction, or from a combination of both. This makes it hard to tell which factor actually caused the effect. Without a careful design that isolates each factor or explicitly tests interactions, the results become confounded—you can’t attribute changes to a single cause. That’s why this situation often leads to confusion about which factor influenced the results.

When more than one factor is varied at once, the observed outcome can result from any one factor, or from their interaction, or from a combination of both. This makes it hard to tell which factor actually caused the effect. Without a careful design that isolates each factor or explicitly tests interactions, the results become confounded—you can’t attribute changes to a single cause. That’s why this situation often leads to confusion about which factor influenced the results.