<![CDATA[This research was aimed to describe the discovery learning model to increase students’ flexibility thinking skills on acid-base matery. The method of the research was quasi-experimental with Non Equivalent Control Group Design. The population of this research was all students grade XI in science class of SMA Negeri 1 Pagelaran whose sit in second semester academic in year 2013/2014. The samples were taken by purposive sampling technique then obtained XI IPA1 and XI IPA2 classes as sample of reseach. The effectiveness of discovery learning model was showed by the significant difference of n-Gain between control and experiment classes. The results showed that the average n-Gain in control and experiment classes respectively 0,34 and 0,63. Proving the hyphothesis (t-test) showed that discovery learning model is effective to increase students flexibility thinking skills on acid-base matery.Tujuan penelitian ini adalah untuk mendeskripsikan model discovery learning dalam meningkatkan keterampilan berpikir fleksibel siswa pada materi asam-basa. Metode dalam penelitian ini adalah kuasi eksperimen dengan Non Equivalent Control Group Design. Populasi dalam penelitian ini adalah semua siswa kelas XI IPA SMA Negeri 1 Pagelaran semester genap Tahun Pelajaran 2013/2014. Sampel diambil dengan teknik purposive sampling sehingga diperoleh kelas XI IPA1 dan XI IPA2 sebangai sampel penelitian. Efektivitas model discovery learning diukur berdasarkan perbedaan n-Gain yang signifikan antara kelas kontrol dan kelas eksperimen. Hasil penelitian menunjukkan bahwa rata-rata n-Gain pada kelas kontrol dan kelas eksperimen sebesar 0,34 dan 0,63. Pengujian hipotesis (uji-t) menunjukkan bahwa model pembelajaran discovery learning efektif dalam meningkatkan keterampilan berpikir fleksibel siswa pada materi asam-basa.Kata kunci: keterampilan berpikir fleksibel, materi asam-basa, model discovery learning]]>
