Identify Students’ Scientific Reasoning Ability at Senior High School

This study aims to identify students' scientific reasoning ability in SMAN 3 Surakarta. The ability of scientific reasoning is an important factor to encourage students' thinking ability in learning. The method used in this study is a descriptive method with 88 students 11 th -grade taken at random. The data of scientific reasoning obtained through written test using the Lawson classroom test of scientific reasoning (LCTSR), instrument test that used consists of 12 items two tier multiple-choice that contains 6 scientific reasoning domain 1) Conservation of Mass and Volume (CMV), 2) Proportional Thinking (PPT), 3) Control of Variables (CV), 4) Probabilistic Thinking (PBT), 5) Correlational Thinking (CT), and 6) Hypothetical-deductive Reasoning (HDR). The domains are used as the basis for grouping students' scientific reasoning abilities into three levels: concrete reasoning, transitional, and formal reasoning. The results showed that 51.14% of the students were at the level of concrete reasoning, 42,05% at the transitional level, and 6,81% at the formal reasoning level. This can be a reflection of whether the physics learning that has been implemented is able to encourage students' scientific reasoning ability. The information can be used as a consideration in the selection of appropriate models, methods, and physics learning media.