Salah satu rekomendasi asesor pada visitasi BAN PT dalam rangka Akreditasi Jurusan Tadris IPA Biologi, Fakultas Tarbiyah dan Keguruan UIN Mataram adalah praktikum Laboratorium IPA dilakukan dengan pola 10x1, sementara penyelenggaraan praktikum yang umum dilaksanakan adalah pola blok 1x10. Tujuan penelitian eksperimental ini adalah menguji efektivitas penyelenggaraan praktikum pola blok 1x10 dan 10x1 sebagai acuan kebijakan praktikum Laboratorium IPA. Efektivitas dilihat dari tiga komponen, yaitu: nilai tes praktikum, nilai laporan praktikum, dan preferensi praktikan dan co-asisten terhadap salah satu pola praktikum. Penelitian dilakukan pada mahasiswa Jurusan S1 PGMI Semester II, Jurusan Tadris IPA Biologi Semester IV, dan Co-Asisten. Rancangan penelitian adalah quasi eksperimental dengan tipe Pre-test–postest Non-Equivalen pada sampel yang diambil secara cluster random sampling. Data dikumpulkan dengan teknik tes, angket, dan wawancara untuk kemudian dianalisis dengan statistik inferensial pada taraf signifikansi 0,05. Hasil penelitian menunjukkan, bahwa nilai tes dan nilai laporan praktikum mahasiswa yang mengikuti praktikum pola blok 10 x 1 lebih tinggi dibanding 1 x 10, tetapi tidak berbeda secara signifikan. Berdasarkan analisis diperoleh 96% mahasiswa lebih menyukai pola praktikum 10 x 1. Dengan demikian, ditinjau dari hasil, salah satu pola praktikum tidak ada yang lebih efektif dibanding yang lain.Organizing Practicum of 1 X 10 and 10 X 1 Block Patterns as a Reference for Science Laboratory Practicum PolicyAbstractOne of the recommendations from BAN PT assessors during the visitation in the Accreditation of Department of Natural Sciences, Faculty of Education and Teacher Training is that practicum at Natural Science Laboratory should be administered in a 10x1 block pattern, while the general administration of practicum pattern is a 1x10 block pattern. This experiment aimed at investigating the effectiveness of the administration of the 1x10 and 10x1 block practicum patterns. The effectiveness was sought out by assessing three components, namely: practicum test scores, practicum report scores and the preferences of practicants and co-assistants to one of the practicum patterns. The participants of this study were the second year undergraduate students of elemetary Education Department and the fourh year undergraduate students of Natural Science Education Department, and co-sssistants. This study was of quasi-experiment using Non-Equivalent Pre-test-postest design and the sample was taken using cluster random sampling technique. The data were collected through test, questionnaire, and interview and then they were analyzed using inferential statistics at the 0.05. significance level. The findings showed that the test and practicum report scores of the students who joined the 10 x 1 block practicum pattern were higher than those who joined 1 x 10 block practicum pattern, yet they did not differ significantly. Based on the analysis, 96% of the students obviously preferred the 10 x 1 block practicum pattern. Thus, based on the results, no one practicum pattern was more effective than the other.