The middle school period is the period when children begin to experience physical, emotional and social development and try to adapt to psychological changes. In this age group, which is seen as a transition period, the child's academic success and acceptance by peers and friends are also important. The problems experienced during this period can continue in adulthood and children are more likely to experience loneliness, sleep disorders, depression, anxiety, eating disorders, low self-esteem, suicidal thoughts, absenteeism and a decrease in academic success. For this reason, early detection of risky behaviors that threaten children's health and evaluation of health promotion practices are very important issues for child health nursing.

In recent years, peer bullying, aggression and social exclusion have increased and continue to increase in the middle school period, also called early adolescence. For this purpose, a study was needed to identify the situation in middle school students and reduce this negativity. In this respect, it is thought that the study will contribute to the literature. In addition, if the hypotheses of the study are confirmed, it is expected that similar training will be provided in other schools and contribute to the reduction of risky behaviors.

The aim of this study is to determine the effects of motivational interviewing-based education on peer bullying, social exclusion and aggression in secondary school students and to offer suggestions for situations where deficiencies are observed based on the findings obtained.

The universe of the study consists of 1 secondary school selected by simple random method from 39 secondary schools located in the city center affiliated to the Muş Provincial Directorate of National Education. G Power 3.1.9.7 program was used to determine the sample size for the study. The program used the ''A priori: compute required sample'' analysis method. Accordingly, when the first type error amount (α = 0.05) was taken at an effect size of 0.365 (Seyhan Şahin & Ayaz-Alkaya, 2024), it was determined that the number of people to be included in the study to reach 99% power was 60 (30 intervention, 30 control).

Experimental and control groups will be determined by simple random method among the students who accept to participate in the research. Pre-test will be applied to the students in the control group, post-test will be applied 6 weeks after the pre-test and control test will be applied 3 months after the post-test. 6-week motivational interview based training will be given to the students in the experimental group after the pre-test. Post-test will be applied at the end of the training and control test will be applied 3 months after the post-test. In the study, first the control group and then the experimental group will be included in the study..

Inclusion Criteria:

• Being 12-13 years old
• Being in one of the 6th and 7th grades of middle school
• Having a high score on the ''Peer Bullying Determination Scale''
• Being willing to participate in the research
• Not having a communication barrier
• The student and their parents having signed the informed consent form.

Exclusion Criteria:

• Having a low score on the ''Peer Bullying Determination Scale''
• The volunteer not wanting to continue during the research
• Encountering any communication barriers during the research
• Answering the data collection forms incompletely or incorrectly