ABSTRAK
Tujuan penelitian ini adalah untuk mengetahui peningkatan prestasi belajar siswa pada mata pelajaran ekonomi kelas X IIS 1 SMA Negeri 5 Surakarta tahun ajaran 2014/2015 melalui penerapan model pembelajaran Group Investigation (GI) dengan mind mapping.
Model penelitian yang digunakan dalam penelitian ini adalah Penelitian Tindakan Kelas. Obyek penelitian ini adalah siswa kelas X IIS 1 SMA Negeri 5 Surakarta Tahun Ajaran 2014/2015 yang berjumlah 31 siswa. Penelitian ini dilaksanakan dengan kolaborasi antara guru kelas, peneliti, dan melibatkan siswa. Teknik pengumpulan data yang digunakan adalah (a) observasi, (b) wawancara, (c) dokumentasi. Prosedur penelitian meliputi tahap (a) perencanaan, (b) tindakan, (c) observasi, (d) refleksi.
Berdasarkan penelitian yang telah dilaksanakan, dapat disimpulkan bahwa terdapat peningkatan prestasi belajar ekonomi melalui penerapan model pembelajaran Group Investigation (GI) dengan mind mapping. Prestasi belajar siswa mengalami peningkatan yaitu sebesar 6,78 (nilai rata-rata pra siklus 72,45 dan nilai rata-rata siklus I 79,23) dan persentase ketuntasan meningkat 16,31% (persentase pra siklus 50,06% dan siklus I 74,19%). Prestasi belajar siswa pada siklus II juga terus mengalami peningkatan yaitu sebesar 5,36 (nilai rata-rata siklus I 79,23 dan nilai rata-rata siklus II 84,59) dan persentase ketuntasan meningkat 19,36% (persentase siklus I 74,19% dan siklus II 93,55%).
Kata kunci: group investigation, mind mapping, prestasi belajar  
ABSTRACT
The objective of research was to find out the improvement of students achievement in economic course of the tenth grade student of one social science program in SMA 5 Surakarta in the school year 2014/2015 through implementing Group Investigation and mind mapping models.
This study was a Classroom Action Research. The subject of research was the tenth grade student of one social science program in SMA 5 Surakarta in the school year 2014/2015 consisting of 31 students. This research was conducted with collaboration between teacher, researcher, and involving student. Techniques of collecting data used were (a) observation. (b) interview. (c) documentation. The research procedure included (a) planning. (b) acting. (c) observing. and (d) reflecting stages.
Based on the research that has been done, it can be concluded that there was an improvement in the economic learning achievement through Group Investigation (GI) and mind mapping models on the tenth grade student of one social science program in SMA 5 Surakarta in the school year 2014/2015. The learning achievement of students increased by 6,78 (from the mean score of 72,45 in prior condition to 79,23 in cycle I) and the percentage passing increased by 16,31% (from 50,06% in prior condition to 74,19% in cycle I). The learning achievement of students in cycle II also increased by 5,36 (from the mean score of 79,238 in cycle I to 84.59 in cycle II) and percentage passing increased by 19,36% (from 74,19% in cycle I to 93,55% in cycle II).
Keywords: group investigation, mind mapping, learning achievement