Abstract
Penelitian ini dilatarbelakangi oleh masih rendahnya kemampuan komunikasi matematis siswa dalam menyampaikan ide, menjelaskan langkah penyelesaian, dan menggunakan simbol matematika secara tepat pada pembelajaran statistika. Penelitian ini bertujuan untuk mendeskripsikan kemampuan komunikasi matematis siswa ditinjau dari self confidence pada materi statistika berbasis STEM di SMP Islam Musthofa Kamal. Penelitian menggunakan pendekatan kualitatif dengan jenis deskriptif. Subjek penelitian terdiri atas 30 siswa kelas VIII yang dipilih menggunakan teknik purposive sampling berdasarkan kategori self confidence tinggi, sedang, dan rendah. Instrumen penelitian meliputi angket self confidence, tes kemampuan komunikasi matematis, pedoman wawancara, dan dokumentasi. Instrumen telah melalui uji validitas isi dan dinyatakan reliabel berdasarkan uji Cronbach’s Alpha dengan koefisien reliabilitas angket sebesar 0,87 dan tes sebesar 0,82 yang termasuk kategori sangat reliabel. Analisis data menggunakan model Miles dan Huberman melalui reduksi data, penyajian data, dan penarikan kesimpulan. Keabsahan data dilakukan melalui triangulasi teknik dan member checking. Hasil penelitian menunjukkan bahwa sebagian besar siswa berada pada kategori self confidence sedang sebanyak 18 siswa, sedangkan 7 siswa berkategori tinggi dan 5 siswa berkategori rendah. Siswa dengan self confidence tinggi memiliki kemampuan komunikasi matematis lebih baik pada indikator written text, drawing, dan mathematical expression dibandingkan kategori sedang dan rendah. Secara umum, kemampuan komunikasi matematis siswa tergolong sangat baik sehingga self confidence berperan penting dalam mendukung kemampuan komunikasi matematis siswa pada pembelajaran statistika berbasis STEM. KataKunci: kemampuan komunikasi matematis, self confidence, statistika, pembelajaran STEM, siswa SMP Analysis of Students’ Mathematical Communication Ability in Terms of Self-Confidence Abstract This study is motivated by the low level of students’ mathematical communication skills in expressing ideas, explaining solution steps, and using mathematical symbols appropriately in statistics learning. The aim of this research is to describe students’ mathematical communication skills in terms of self-confidence in STEM-based statistics learning at SMP Islam Musthofa Kamal. This study uses a qualitative approach with a descriptive design. The research subjects consisted of 30 eighth-grade students selected using purposive sampling based on high, medium, and low self-confidence categories. The research instruments included a self-confidence questionnaire, a mathematical communication skills test, interview guidelines, and documentation. The instruments were validated through content validity by expert validators and were declared reliable based on Cronbach’s Alpha reliability test, with reliability coefficients of 0.87 for the questionnaire and 0.82 for the test, both categorized as highly reliable. Data were analyzed using the Miles and Huberman model, including data reduction, data display, and conclusion drawing. Data validity was ensured through technique triangulation and member checking. The results show that most students are in the medium self-confidence category (18 students), while 7 students are in the high category and 5 students are in the low category. Students with high self-confidence demonstrate better mathematical communication skills in written text, drawing, and mathematical expression indicators compared to those in the medium and low categories. Overall, students’ mathematical communication skills are classified as very good, indicating that self-confidence plays an important role in supporting students’ mathematical communication skills in STEM-based statistics learning.