<![CDATA[Abstrak: Penelitian ini bertujuan untuk meningkatkan aktivitas dan hasil belajar siswa kelas XI IPA 2 SMA Negeri 1 Sungai Ambawang pada materi koloid melalui model pembelajaran kooperatif tipe Two Stay Two Stray. Bentuk penelitian yang digunakan adalah penelitian tindakan kelas (PTK). Subjek penelitian adalah siswa kelas XI IPA 2 SMA Negeri 1 Sungai Ambawang. Lembar observasi dan tes hasil belajar digunakan sebagai instrumen penelitian. Sebelum digunakan instrumen tersebut di uji validitas dan reliabilitasnya. Validitas isi yang digunakan adalah uji gregory dan reliabilitas yang digunakan dadalah rumus alpha chronbach. Dari hasil perhitungan validitas isi tergolong dalam kategori tinggi dan reliabilitas tergolong dalam kategori sedang. Tindakan dalam penelitian ini terdiri dari 2 siklus dan setiap siklus terdiri dari 4 tahap yaitu perencanaan, tindakan, observasi dan refleksi. Hasil penelitian menunjukkan terdapat peningkatan terhadap aktivitas dan hasil belajar. Peningkatan aktivitas siswa sebesar 2,03%. Hasil penelitian juga menunjukkan terdapat peningkatan hasil belajar siswa 3,74% Kata kunci: Two Stay Two Stray (TSTS), Aktivitas belajar, hasil belajar, Koloid Abstract: This research aims to improve student’s activities and student’s achievement in second eleventh grade student of SMA Negeri 1 Sungai Ambawang in  koloid material through kooperatif tipe Two Stay Two Stray learning model. The form of this research was classrom action research. The subject of this research was students of second eleventh grade students of SMA Negeri 1 Sungai Ambawang. Observation sheet and learning achievement test was used as the research instrument. Before used the instrument, the validity and reliability of the instrument has been checked. Content validity that used was gregory test and chonbach alpha for the reliability. From the result of content validity that include to the high category and reliability include to the average category. The action in this research consists of two cycle and there are 4 step in each cycle. They are planning, action, observation, and reflexion. The result of this research shows that there was an improving of students' activity and students' achievement. Thus, the improving of students' activity was 2,03%. The result of this research also shows that there was improving in students learning achievement, it was 3,74%. Key Word: Two Stay Two Stray (TSTS), activity, students learning achievement, Koloid  ]]>
