<![CDATA[This quasi experimental research aimed to know the effectiveness of discovery learning viewed by students conceptual understanding and prior knowledge of mathematics. The design which was used was pretest-posttest control group design. The population of this research was all students of grade seven of SMPN 3 Way Pengubuan in academic year of 2014/2015 and the samples of this research were students of VIIA and VIIB class that were determined by purposive sampling. The data of students understanding of mathematical concepts were obtained by essay testand the data of students prior knowledge of mathematics were obtained by multiple-choice test. This research concluded that the implementation of discovery learning was effective viewed by the students conceptual understanding and prior knowledge of mathematics, and more effective than conventional learning.Penelitian eksperimen semu ini bertujuan untuk mengetahui efektivitas discovery learning ditinjau dari kemampuan pemahaman konsep dan kemampuan awal matematika siswa. Desain yang digunakan adalah preetest-posttest control group design. Populasi penelitian ini adalah seluruh siswa kelas VII SMP Negeri 3 Way Pengubuan pada tahun akademik 2014/2015 dan sampel penelitian ini adalah siswa kelas VIIA dan VIIB yang ditentukan dengan teknik purposive sampling. Data kemampuan pemahaman konsep matematis siswa diperoleh dari tes uraian dan data kemampuan awal matematika diperoleh dari tes pilihan berganda. Penelitian ini menyimpulkan bahwa penerapan discovery learning efektif ditinjau dari kemampuan pemahaman konsep matematis siswa dan kemampuan awal matematika siswa, serta lebih efektif dibandingkan pembelajaran konvensional.Kata kunci: discovery learning, kemampuan awal, pemahaman konsep]]>
