pengembangan bahan ajar geometri smp berbasis cognitive load theory berorientasi pada prestasi belajar siswa

Penelitian ini bertujuan untuk menghasilkan bahan ajar geometri SMP berbasis Cognitive Load Theory (CLT) serta mendeskripsikan kualitas kevalidan, kepraktisan dan keefektifan bahan ajar tersebut. Bahan ajar yang dikembangkan berupa buku pengayaan geometri untuk SMP kelas VII dan VIII sesuai dengan Kurikulum 2006. Jenis penelitian ini adalah penelitian kualitatif dengan menggunakan model penelitian desain dari Plomp yang terdiri atas tiga tahap: preliminary research, prototyping phase, dan assessment phase. Subjek coba terdiri dari 32 siswa kelas VII dan 32 siswa kelas VIII dari dua SMP Negeri di Kabupaten Wonosobo, beserta masing-masing satu guru matematika dari sekolah tersebut. Subjek coba yang menggunakan bahan ajar ini telah menguasai kompetensi dasar pembelajaran. Penelitian ini menghasilkan bahan ajar geometri SMP berbasis CLT yang memenuhi aspek kevalidan, kepraktisan dan keefektifan. Hasil evaluasi formatif 1 menyatakan bahwa bahan ajar yang dikembangkan memenuhi kriteria valid. Hasil evaluasi formatif 2 dan evaluasi sumatif menyatakan bahwa bahan ajar memenuhi kriteria praktis. Keefektifan bahan ajar terlihat dari hasil penilaian prestasi belajar yang menunjukkan bahwa persentase siswa kelas VII yang mencapai KKM adalah 78% dengan rata-rata nilai klasikal 78 dan persentase siswa kelas VIII yang mencapai KKM adalah 75% dengan rata-rata nilai klasikal 80. Secara keseluruhan, hasil penelitian menunjukkan bahwa bahan ajar yang dikembangkan layak digunakan. Kata Kunci: bahan ajar, pengayaan, geometri SMP, Cognitive Load Theory.   Developing Geometry Learning Materials for Junior High School Based on Cognitive Load Theory with Regard to Student’s Achievement   Abstract This study was aimed to develop a geometry learning materials for junior high school based on Cognitive Load Theory (CLT) and to describe the quality with respect to the validity, practicality, and effectiveness of the developed learning materials consisting of advanced geometry for seventh and eighth graders referring to the Curriculum of 2006. The research was a qualitative study using design research model suggested by Plomp, involving three phases: preliminary research, prototyping, and assessment. Research participants were 32 seventh and 32 eighth grade students at two public junior high schools in Wonosobo, as well as their mathematics teachers. These students had acquired minimum competencies to use the learning materials. This research resulted in junior high school geometry learning materials based on CLT, which satisfies the validity, practicality, and effectiveness aspects. The result of first formative evaluation informed that learning materials were categorized valid. The results of second formative evaluation and summative evaluation revealed that the learning materials were categorized practical. The effectiveness of learning materials could be seen from the results of the achievement test which showed that the percentage of seventh graders who passed the minimum criteria was 78%, with an average test score was 78; and the percentage of eighth graders who passed the minimum criteria was 75%, with an average test score was 80. Overall, the results showed that the developed learning materials can be used widely. Keywords: learning materials, advance, geometry SMP, Cognitive Load Theory.