Methodology is the foundation for designing an effective intervention. In school-based studies, the term "Fidelity to the treatment plan" or "intervention plan" includes methodological strategies essential for monitoring practical interventions. It ensures that the intervention is implemented as intended and that its key components contribute to producing desired outcomes. Fidelity to the treatment plan is a multidimensional concept that includes adherence to the intervention, intervention quality, intervention quantity, and intervention process. This framework enables researchers to ensure the validity and reliability of clinical interventions. Reporting on adherence to treatment and the implementation of an intervention plan offers insights into how to execute the intervention, the suitability of the intervention plan within its intended context, and the challenges encountered during implementation and maintenance. Failure to report on these aspects may result in a lack of information for other researchers and users about the project's conditions. Therefore, determining the optimal level of Fidelity to the treatment plan in interventions and measurements is crucial. While researchers have increasingly recognized the importance of Fidelity to the treatment plan in recent decades, this area still requires more serious attention. Loyalty to the treatment plan in school-based interventions, given the diverse contexts and structures of schools, as well as the dynamic school environment, demands special consideration. Some researchers and reputable publications have suggested that without reporting Fidelity to the treatment plan, it is impossible to ascertain whether behavioral changes in subjects are truly influenced by the independent variable. This article aims to outline the dimensions of Fidelity to the treatment plan in school-based interventions.