Posternak and Miller's (2001) findings showed that depressed participants on a wait-list for treatment improved by an average of 10% to 15% without formal therapy. What is the primary reason this finding is significant for the design of psychological research?

In clinical research on depression, researchers must distinguish specific treatment effects from natural recovery. Based on the findings of Posternak and Miller (2001), match each study scenario with the conclusion that correctly applies their 10% to 15% improvement threshold.

A researcher finds that a new counseling technique leads to a 30% reduction in depression symptoms. Arrange the logical steps required to analyze this result using the findings of Posternak and Miller (2001) to isolate the specific benefit of the technique.

Based on the findings of Posternak and Miller (2001), a researcher can validly conclude that a new therapy is effective if it produces a $14$ reduction in depression symptoms in a study that lacks a control group.

In Posternak and Miller's (2001) meta-analysis of depression treatments, which specific group of participants showed an average improvement of $10\%$ to $15\%$ in their symptoms despite not receiving formal therapy?

Posternak and Miller's (2001) study showing that wait-list control participants improved by $10\%$ to $15\%$ without therapy demonstrates that simply observing symptom reduction in a treated group is not sufficient to prove a therapy is effective.

In Posternak and Miller's 2001 meta-analysis of depression treatments, participants in wait-list control conditions who had not yet received any formal therapy still showed an average improvement of _____ to 15% in their depression symptoms.