<![CDATA[ABSTRACT Oppositional behavior is one of the behavioral problems commonly found among junior high school students, characterized by arguing, refusing instructions, violating rules, becoming easily angry, disturbing peers, and displaying defiant attitudes toward authority figures. If not appropriately addressed, such behavior may interfere with the learning process and students’ social-emotional development. This study aimed to determine the effect of the behavior contract technique on oppositional behavior among eighth-grade students at SMP Negeri 2 Lingsar in the 2026/2027 academic year. This study employed a quantitative approach with a pre-experimental one-group pretest-posttest design. The participants were 6 students selected through purposive sampling from a population of 108 eighth-grade students based on initial assessment results indicating high and very high levels of oppositional behavior. Data were collected using a 34-item oppositional behavior questionnaire with four response options. The behavior contract intervention was implemented through group counseling services involving behavioral agreement, periodic monitoring, and reinforcement. The data were analyzed using a Paired Sample t-Test with the assistance of SPSS. The results showed that the mean oppositional behavior score decreased from 113.83 in the pretest to 78.67 in the posttest, representing a decrease of 35.17 points. The Paired Sample t-Test yielded a significance value of 0.000 < 0.05, indicating that H0 was rejected and Ha was accepted. Therefore, the behavior contract technique implemented through group counseling services had a significant effect on reducing students’ oppositional behavior. variabel utama dan konteks penelitian. ABSTRAK Perilaku oposisi merupakan salah satu permasalahan perilaku pada peserta didik Sekolah Menengah Pertama (SMP) yang ditandai dengan perilaku membantah, menolak instruksi, melanggar aturan, mudah marah, mengganggu teman, dan menentang figur otoritas. Perilaku tersebut apabila tidak ditangani secara tepat dapat menghambat proses pembelajaran serta perkembangan sosial-emosional peserta didik. Penelitian ini bertujuan untuk mengetahui pengaruh teknik behavior contract terhadap perilaku oposisi peserta didik kelas VIII SMP Negeri 2 Lingsar Tahun Pelajaran 2026/2027. Penelitian ini menggunakan pendekatan kuantitatif dengan desain pre-experimental one-group pretest-posttest. Subjek penelitian berjumlah 6 peserta didik yang dipilih melalui teknik purposive sampling dari 108 peserta didik kelas VIII berdasarkan hasil pengukuran awal dengan kategori perilaku oposisi tinggi dan sangat tinggi. Data dikumpulkan menggunakan angket perilaku oposisi yang terdiri atas 34 item dengan empat alternatif jawaban. Intervensi teknik behavior contract dilaksanakan melalui layanan konseling kelompok dengan tahapan penyusunan kesepakatan perilaku, pemantauan, dan pemberian penguatan. Data dianalisis menggunakan Paired Sample t-Test dengan bantuan SPSS. Hasil penelitian menunjukkan bahwa rata-rata skor perilaku oposisi menurun dari 113,83 pada saat pretest menjadi 78,67 pada saat posttest, dengan penurunan sebesar 35,17 poin. Hasil uji Paired Sample t-Test menunjukkan nilai signifikansi 0,000 < 0,05, sehingga H0 ditolak dan Ha diterima. Dengan demikian, teknik behavior contract melalui layanan konseling kelompok berpengaruh signifikan dalam menurunkan perilaku oposisi peserta didik.]]>
