<![CDATA[Abstract This classroom action research observed students' writing abilities. This study aims to improve the writing skills of class 1A students in learning Indonesian. This study uses the Problem Based Learning learning method. The research was conducted at SD Kanisius Kalasan Yogyakarta involving 22 students consisting of 11 boys and 11 girls enrolled in the 2022/2023 school year. This study uses the research design of Kemmis and Mc. Taggart which consists of two cycles. Where each cycle is held in two meetings in class and each cycle consists of four stages, namely planning, implementing, observing, and reflecting. The results showed that the pre-cycle action obtained 70% classical absorption and 36% classical learning mastery. Cycle I obtained 75% classical absorption and 59% classical learning mastery. In cycle II there was an increase with the acquisition of 83% classical absorption while the classical learning mastery was 81%. Thus it can be concluded that learning using the Problem Based Learning (PBL) method can improve students' writing skills in class I SD Kanisius Kalasan. . Kata Kunci: Writing Ability, Language, Indonesian and Problem Based Learning Methods. Abstrak Penelitian tindakan kelas ini mengamati mengenai kemampuan menulis siswa. Penelitian ini bertujuan untuk meningkatkan kemampuan menulis siswa kelas 1A pada pembelajaran Bahasa Indonesia. Penelitian ini menggunakan metode pembelajaran Problem Based Learning. Penelitian dilaksanakan di SD Kanisius Kalasan Yogyakarta dengan melibatkan 22 orang siswa terdiri dari 11 laki-laki dan 11 perempuan yang terdaftar pada tahun ajaran 2022/2023. Penelitian ini menggunakan desain penelitian Kemmis dan Mc. Taggart yang terdiri atas dua siklus. Dimana setiap siklus dilaksanakan dua kali pertemuan di kelas dan setiap siklus terdiri empat tahap yaitu perencanaan, pelaksanaan, observasi, dan refleksi. Hasil penelitian menunjukkan bahwa pada tindakan pra siklus diperoleh daya serap klasikal 70% dana ketuntasan belajar klasikal 36%. siklus I diperoleh daya serap klasikal 75% dana ketuntasan belajar klasikal 59%. Pada siklus II terjadi peningkatan dengan perolehan daya serap klasikal 83% sedangkan ketuntasan belajar klasikal 81%. Dengan demikian dapat disimpulkan bahwa pembelajaran dengan menggunakan metode Problem Based Learning (PBL) dapat meningkatkan kemampuan menulis siswa di kelas I SD Kanisius Kalasan.]]>
