Siyampriyanti, R2013-01-032013-01-032013-01-03Wahono.M.Sihttp://repository.unri.ac.id:80/handle/123456789/1061Penerapan Model Pembelajaran Aptitude Treatment Interaction (Ati) Untuk Meningkatkan HasilPENERAPAN MODEL PEMBELAJARAN APTITUDE TREATMENT INTERACTION (ATI) UNTUK MENINGKATKAN HASIL BELAJAR SISWAPADA POKOK BAHASAN REAKSI REDOKS DI KELAS X SMAN 5 PEKANBARU Ria Siyampriyati, Johni Azmi, dan Jimmi Copriady Program Studi Pendidikan Kimia FKIP Universitas Riau Email: ry_1891@yahoo.com Abstract A research on the application of the learning model type Aptitude Treatment Interaction (ATI) has been conducted. This research aimed to increase students’ achievement in learning oxidation-reduction reaction (redox) at grade X class of SMAN 5 Pekanbaru. The students were divided into three groups with different ability (high, moderate, and low). This research was used pretest-posttest control group design. Hypothesis was measured by n-gain and t-test. From the result ngain experiment class is bigger than n-gain control class (0,89 > 0,71; 0,72 > 0,53; and 0,57 > 0,55) and t observed was 1,90 meanwhile t table was 1,67. It indicated that t observed > than t table. It means the Ho was rejected and H1 was accepted. Therefore, it could be concluded that the application of the learning model type ATI was able to increase students’ learning achievement in redox reaction at X class of SMAN 5 Pekanbaru.en-USlearning model,Aptitude Treatment Interaction (ATI),learning achievement, redox reactionArticle