<![CDATA[This study was motivated by the low problem-solving ability of early childhood learners, which is caused by learning activities that are still teacher-centered and do not actively involve children in the learning process. This study aimed to determine the effect of the Project Based Learning (PjBL) model on the problem-solving abilities of early childhood students at TK Idhata Pontianak. This study employed a quantitative approach using a One Group Pretest–Posttest Design. The research sample consisted of Group B children at TK Idhata Pontianak aged 5–6 years, totaling 16 children, consisting of 10 boys and 6 girls. Data were collected using an observation sheet of children’s problem-solving abilities based on predetermined indicators. Data analysis was conducted using descriptive analysis, normality testing, paired sample t-test, and N-Gain calculation. The results showed a significant difference in children’s problem-solving abilities before and after the implementation of the Project Based Learning model, as indicated by a t-test significance value of less than 0.05. In addition, the N-Gain results indicated an improvement in children’s problem-solving abilities in the moderate to high category. Based on these results, it can be concluded that the implementation of the Project Based Learning model has a significant effect on improving the problem-solving abilities of early childhood students at TK Idhata Pontianak. Keywords: Project Based Learning, Problem-Soving Ability, Early Childhood ABSTRAK Penelitian ini didasari oleh kemampuan pemecahan masalah anak usia dini yang rendah karena pembelajaran masih bersifat teacher-centered dan kurang melibatkan anak secara aktif dalam proses belajar. Penelitian ini bertujuan untuk mengetahui pengaruh model Project Based Learning (PjBL) terhadap kemampuan pemecahan masalah anak usia dini di TK Idhata Pontianak. Penelitian ini menggunakan pendekatan kuantitatif dengan desain One Group Pretest–Posttest Design. Sampel penelitian adalah anak kelompok B di TK Idhata Pontianak yang berusia 5–6 tahun dengan jumlah 16 orang anak, terdiri atas 10 anak laki-laki dan 6 anak perempuan. Teknik pengumpulan data menggunakan lembar observasi kemampuan pemecahan masalah anak berdasarkan indikator yang telah ditetapkan. Analisis data dilakukan menggunakan analisis deskriptif, uji normalitas, uji t berpasangan (paired sample t-test), dan perhitungan N-Gain. Hasil penelitian menunjukkan adanya perbedaan yang signifikan antara kemampuan pemecahan masalah anak sebelum dan sesudah penerapan model Project Based Learning, yang ditunjukkan oleh nilai signifikansi uji t lebih kecil dari 0,05. Selain itu, hasil perhitungan N-Gain menunjukkan adanya peningkatan kemampuan pemecahan masalah anak pada kategori sedang sampai dengan tinggi. Oleh karena itu, dinyatakan penerapan model Project Based Learning berpengaruh signifikan dalam meningkatkan kemampuan pemecahan masalah anak usia dini di TK Idhata Pontianak. Kata kunci: Project Based Learning, kemampuan pemecahan masalah, anak usia dini.]]>
