The sample size was determined using the G-Power 3.01 program (G*Power 3.1 Manual, 2017), based on a Type I error of 0.05, a power of 0.95, and an effect size of f=0.55. According to these calculations, the sample size was set to a minimum of 10 individuals. Since the study was a pre-test post-test control group design and to prevent the reduction of internal validity due to any data loss, it was decided that each group (experimental and control) should have 20 participants.

The school that formed the experimental group had only one preschool class, comprising 21 students.

The control group's school also had one preschool class, with 19 students making up the control group.

Students in the study group were subjected to a 24-session RAP, including entertaining games. This program was conducted by the first-name researcher, who had completed their undergraduate education in preschool education and was supported by the second and third-named researchers as assistant instructors. The 24-session program, which included rhythm, balance, and patience acquisition games, was planned according to a game theory model that primarily aimed to entertain children. The program, aimed at developing children's self-regulation skills based on fundamental reflections of the model, would consist of simple rule-based entertaining games. Before the program's application, researchers provided information about the research and program to the experimental group, and verbal consent was obtained.

Preschool Self-Regulation Assessment: The 'Preschool Self-Regulation Assessment' scale measured the self-regulation skills of the children. Developed by Smith-Donald et al. (2007), this assessment tool allows for a performance-based evaluation. The Practitioner's Assessment Form within the scale provides the evaluator with the opportunity to assess the child's emotions, attention level, and behaviors based on the interaction between the practitioner and the child. The Practitioner's Assessment Form is a rubric-type rating scale scored from 0 to 3. The Turkish adaptation of the scale was carried out by Tanrıbuyurdu and Yıldız in 2012. The factor analysis performed within the scope of construct validity has determined that the scale has a two-factor structure: Attention/Impulse Control and Positive Emotion. The scale consists of 16 items, and the reliability coefficient (α) of the entire scale has been determined as .83.