Which of the following could be a dependent variable in a rehabilitation study evaluating a new therapy?

• A. The type of therapy used
• B. ROM
• C. Group assignment
• D. Therapist experience level

Answer: (B)

When evaluating a rehabilitation therapy, the key idea is that the dependent variable is the outcome you measure to see if the intervention works. Range of motion is a direct, measurable outcome that can change in response to therapy, making it a classic dependent variable. The type of therapy used is what you manipulate to test its effect, so it’s an independent variable. Group assignment relates to how you structure the study to compare groups and isn’t the outcome being measured. Therapist experience level describes who delivers the therapy, a provider characteristic that can influence results but is not the outcome itself. Therefore, ROM is the dependent variable.