<![CDATA[This research was aimed to describe the misconceptions and factors that can affected students. The samples were 8th grade students of SMPN 9 Bandar Lampung that was selected by random sampling. The design of this research was descriptive. Data was collected by written test and analyzed with Certainty of Response Index, and student’s questionnaire were analyzed by Pearson Product Moment Correlation test. Study result showed that percentage of students on all concept was 61,10%. Percentages of misconceptions students on photosynthesis, respiration and photosynthesis and respiration were 57,55%, 64,96%, and 62,39%. Misconception was influenced by student interest in learning factor. This misconception on 8th grade students of SMPN 9 Bandar Lampung was high category in photosynthesis and respiration and influenced by student low interest in learning. Penelitian bertujuan mendeskripsikan miskonsepsi siswa dan faktor yang mempengaruhi miskonsepsi siswa. Sampel penelitian adalah siswa kelas VIII SMPN 9 Bandar Lampung dipilih secara random sampling. Desain penelitian menggunakan deskriptif sederhana. Pengumpulan data dengan tes tertulis dan dianalisis menggunakan Certainty of Response Index (CRI), kemudian angket siswa dianalisis menggunakan uji korelasi Pearson Product Moment. Hasil penelitian menunjukkan siswa miskonsepsi pada keseluruhan materi sebesar 61,10%. Siswa yang miskonsepsi pada konsep Fotosintesis, Respirasi, serta Fotosintesis dan Respirasi sebesar 57,55%, 64,96%, dan 62,39%. Miskonsepsi dipengaruhi faktor minat belajar siswa. Dengan demikian, bahwa siswa kelas VIII SMPN 9 Bandar Lampung yang mengalami miskonsepsi yang termasuk dalam kategori “tinggi” pada konsep Fotosintesis dan Respirasi, dan dipengaruhi oleh minat belajar siswa yang rendah. Kata kunci: Certainty Of Respons Index, fotosintesis, miskonsepsi, respirasi]]>
