<![CDATA[In mathematics a lot of complaints from teachers because of lack of achievement and motivation of one of the earliest achievements to improve learning outcomes and student motivation is a cooperative learning model type group investigation. This study aims to determine the increase in student achievement and learning motivation among students who learn through cooperative learning model type Group Investigation with students who learn through conventional learning models. This study is a quasi-experiment study research design of pre-test post-test control group design. The population is all students of class XI SMA Negeri 8 Banda Aceh by taking samples of two classes (the experimental class and control class) via random sampling of eight parallel classes available. The data collection was done using two kinds of instruments that test and non test. Tests include pretest and posttest, while non-test includes a questionnaire to students' motivation. To see the difference in achievement and increase students' motivation between experimental class and control class used the t-test. Based on the survey results revealed that 1) the increase in student achievement which acquire learning through cooperative learning model type Group Investigation better than students who received conventional learning, and 2) increase students' motivation obtain cooperative learning type Group Investigation better than in students who obtain conventional learning. The use of cooperative learning model type Group Investigation in learning proven to improve student achievement and motivation to learn, so it is suggested that other researchers can apply in mathematics learning another topic.]]>
