Which statement is true regarding the use of placebos in research?

The statement indicating that placebo groups are critical in process research is correct because they serve an essential function in controlling for the effects of expectations and biases in a study. In experimental research, especially in clinical trials and psychological studies, placebos help researchers determine whether the observed effects can be attributed to the treatment being tested or if they stem from participants' expectations of the treatment itself. This control helps establish the efficacy of the intervention being studied by providing a baseline for comparisons. By utilizing a placebo group, researchers can isolate the specific impact of the active treatment and differentiate it from any psychological effects related to simply receiving treatment. This design enhances the validity and reliability of the research findings.