Tujuan penelitian ini adalah untuk mengetahui peningkatan kemampuan leadership dan minat belajar peserta didik kelas X IMERSI 1 SMA N 2 Karanganyar setelah melalui metode group investigation.
Penelitian ini merupakan penelitian tindakan kelas (PTK). Penelitian dilaksanakan dalam dua siklus, dengan tiap siklus terdiri atas perencanaan, pelaksanaan tindakan, observasi, dan refleksi. Subjek penelitian adalah peserta didik kelas X IMERSI 1 SMA N 2 Karanganyar yang berjumlah 24 peserta didik. Sumber data berasal dari guru dan peserta didik. Teknik pengumpulan data adalah dengan observasi, wawancara, angket, dokumentasi dan tes. Validitas data menggunakan teknik triangulasi. Analisis data menggunakan teknik scoring dan analisis kritis. Prosedur penelitian adalah model spiral yang saling berkaitan.
Hasil penelitian menunjukkan bahwa melalui penerapan metode group  investigation dapat meningkatkan kemampuan leadership dan minat belajar peserta didik dari prasiklus ke siklus I dan dari siklus I ke siklus II. Proses pembelajaran prasiklus berpusat pada guru dengan menggunakan metode ceramah sehingga kemampuan leadership dan minat belajar peserta didik rendah. Peningkatan terjadi pada siklus I. Kemampuan leadership dan minat belajar peserta didik meningkat meskipun belum optimal. Pelaksanaan siklus II menyebabkan kemampuan leadership dan minat belajar peserta didik meningkat mencapai indikator ketercapaian yang diinginkan.
Simpulan penelitian ini adalah penerapan metode group investigation meningkatkan  kemampuan leadership dan minat belajar peserta didik terhadap materi hidrosfer pada mata pelajaran geografi di kelas X IMERSI 1 SMA N 2 Karanganyar.
   
Kata kunci: Group Investigation, Kemampuan Leadership, Minat Belajar

The aim of this research was to determine imrpovement leadership skills and student’s interest in learning of students in tenth grade Imersi 1 SMA N 2 Karanganyar after do group investigation methods.
This research is a Classroom Action Research. The experiment was conducted in two cycles, with each cycle consisting of planning, action, observation, and reflection. The subjects were students of tenth grade Imersi 1 SMA N 2 Karanganyar amounting to 24 learners. Source data comes from teachers and learners. The data collection technique is by observation, interviews, questionnaires, documentation and testing. The validity of the data using the technique of triangulation method. Analysis of the data using scoring and critical analysis. Research  procedures are interrelated spiral model. 

The results show that through the application of group investigation methods can improve leadership skills and interests of learners from pre-cycle to the first cycle and from first cycle to second cycle. Pre-cycle learning process centered on the teacher using the lecture method so that the leadership skills and interests of learners low. The increase occurred in first cycle leadership ability and interests of learners increased although not optimal. Implementation of the second cycle causes leadership skills and interests of learners increased to the desired achievement indicators.
The conclusions of this research is the application of methods of group investigation improve leadership skills and interests of learners against hydrosphere material on the subjects of geography in tenth grade Imersi 1 SMA N 2 Karanganyar.
   
Keywords: Group Investigation, Leadership Capabilities, Interests Learning