Penelitian ini bertujuan untuk mendeskripsikan kesalahan siswa introver dan ekstrover serta penyebab kesalahannya berdasarkan kriteria Newman dalam menyelesaikan soal cerita materi program linear. Jenis penelitian yang digunakan adalah penelitian kualitatif deskriptif. Terdapat 4 subjek penelitian yaitu 2 siswa dengan tipe kepribadian introver dan 2 siswa dengan tipe kepribadian ekstrover. Teknik pengumpulan data yang digunakan adalah angket, tes soal, dan wawancara. Instrumen yang digunakan dalam pengumpulan data adalah angket tipe kepribadian, tes soal materi program linear dan pedoman wawancara. Teknik analisis data meliputi kondensasi data, penyajian data dan menarik kesimpulan. Hasil penelitian menunjukkan bahwa siswa introver melakukan kesalahan transformasi, kesalahan keterampilan proses, dan kesalahan penulisan jawaban akhir. Sedangkan siswa ekstrover melakukan kesalahan membaca, kesalahan memahmai, kesalahan transformasi, kesalahan keterampilan soal, dan kesalahan penulisan jawaban akhir. Penyebab kesalahan siswa introver berdasarkan prosedur Newman adalah adanya kebiasaan salah yang tidak diluruskan guru, prinsip siswa tidak menuliskan kendala tak negatif, merasa tertekan karena dibatasi oleh waktu dalam mengerjakan soal. Sedangkan penyebab kesalahan siswa ekstrover adalah siswa ekstrover cenderung tergesa-gesa dalam menyelesaikan soal, tidak dapat menghubungkan informasi-infoemasi pada soal, kurang mengusai materi prasyarat dan tidak melakukan pengecekan ulang terhadap hasil jawabannya.Kata Kunci: Kesalahan, Soal Cerita, Program Linear, Kriteria Newman, Introver dan ekstrover.This study aims to describe the errors of introverted and extroverted students and the causes of their errors based on Newman's criteria in solving linear programming problems. The type of research used is descriptive qualitative research. There are 4 research subjects, namely 2 students with an introverted personality type and 2 students with an extroverted personality type. The research consisted of 2 students with an introverted personality type and 2 students with an extroverted personality type. Data collection techniques used are questionnaires, test questions, and interviews. The instruments used in data collection were personality type questionnaires, linear program material tests and interview guidelines. Data analysis techniques include data condensation, data presentation and drawing conclusions. The results showed that introverted students transformation error, process skills error and enconding error. Meanwhile, extroverted students make are reading error, comprehension error, transformation error, process skills error and enconding error. The causes of introverted students' errors based on the Newman procedure are wrong habits that are not corrected by the teacher, the principle of students not writing down non-negative constraints, feeling pressured because they are limited by time in doing questions. While the causes of extroverted students' errors are extroverted students who tend to be in a hurry in solving problems, cannot connect information to questions, do not master the prerequisite material and do not re-check the results of their answers.Keywords: Error, Story Problem, Linear program, Neman’s Criteria, Introvert and Extrovert.