Question

correctly match each threat to the validity of outcome research with its definition.
nonspecific treatment effects
natural improvement
placebo effect
people get better over time, even without treatment.
people get better by coming to therapy, even though it doesnt matter what actually happens at the therapy sessions.
improvements occur as a result of the expectation that one will get better rather than from the actual effects of a treatment.

Explanation:

• Nonspecific treatment effects: The key here is that the act of attending therapy (regardless of the specific content) leads to improvement. So it matches "People get better by coming to therapy, even though it doesn't matter what actually happens at the therapy sessions."
• Natural improvement: This is about improvement occurring over time without any treatment, so it matches "People get better over time, even without treatment."
• Placebo effect: This is about improvement due to the expectation of getting better (not the actual treatment), so it matches "Improvements occur as a result of the expectation that one will get better rather than from the actual effects of a treatment."

Answer:

• Nonspecific treatment effects: People get better by coming to therapy, even though it doesn't matter what actually happens at the therapy sessions.
• Natural improvement: People get better over time, even without treatment.
• Placebo effect: Improvements occur as a result of the expectation that one will get better rather than from the actual effects of a treatment.