<p><strong>Abstract:</strong> This research aims to develop writing skill essay and short story learning materials for santri with integrate project based learning models. Using ADDIE models, this research produce a learning materials with four part. Project based learning is integrated on the part called “<em>Proyek Keren Kita</em>” (Our Cool Project). This product verified to materials expert, learning media expert, and audience. Based on the verification and test obtained percentage of eligibility aspect is 93,75%, feasibility aspects 100%, graphics aspects 99,3%, language aspects 100%, interestness of teaching materials 85,28%, and ease of understanding aspects 86,82% that means the producs are feasible to be used and disseminated.</p><strong>Abstrak:</strong><em> </em>Penelitian ini bertujuan untuk menghasilkan produk bahan ajar keterampilan menulis esai dan cerita pendek untuk santri yang berbasis <em>project based learning</em>. Metode pengembangan yang digunakan dalam penelitian ini adalah metode ADDIE. Secara umum bahan ajar yang dihasilkan terdiri dari empat bagian. Metode <em>project</em> <em>based learning</em> diintegrasikan ke dalam bahan ajar secara langsung dalam aktivitas yang diberi nama “Proyek Keren Kita”. Produk tersebut selanjutnya diujicobakan kepada ahli materi, ahli media dan pengguna/santri. Berdasarkan uji coba tersebut diperoleh persentase aspek kelayakan isi sebesar 93,75%, aspek kelayakan penyajian 100%, aspek kegrafikan 99,3%, aspek kebahasaan 100%, aspek kemenarikan bahan ajar 85,28% dan aspek kemudahan pemahaman bahan ajar 86,82% yang berarti bahan ajar ini layak untuk digunakan dan disebarluaskan.

This study aims to develop an assessment instrument of mathematical problem-solving skills in senior high school. The developed assessment instrument includes instrument outlines, items of mathematical problem-solving skill in senior high school instrument, and scoring guidelines. The development procedures include 1) Planning the test, 2) Trying out the test, and 3) Establishing the Validity Test, 4) Establishing Test Reliability, and 5) Interpreting the Test Score. The trial was conducted on 508 respondents involving 4 experts and 1 practitioner as raters. The interpretation of the results of the trial is intended to find out the instrument construction and the validity and reliability of the assessment instrument. A problem-solving skill assessment instrument has been validated by the raters. Indicators to be measured include understanding problems, formulating strategies, implementing the strategies, and interpreting the results. The reliability coefficient of the results of the trial is categorized as good in which the Cronbach Alpha value is 0.82. Therefore, the developed instrument can be used to measure the mathematical problem-solving skills in senior high school.