Development of Scientific Explanation Ability on Earth and its Changes through Model-Based Learning Management of Grade 8 Students

Abstract

This research aimed to compare the scientific explanation ability of eighth-grade students on the topic "Earth and Changes" before and after learning through model-based learning instruction. The research sample consisted of 32 eighth-grade students from one classroom at Anuban Penprachehanukul School, Phen District, Udon Thani Province, in the second semester of the 2025 academic year, selected through cluster random sampling. This research employed an experimental design using a one-group pretest-posttest design. The research instruments included four model-based learning lesson plans on "Earth and Changes" and a scientific explanation ability test comprising five scenarios, each containing three sub-questions: claim, evidence, and reasoning. Data were analyzed using frequency, mean, percentage, standard deviation, and dependent t-test. The research findings revealed that eighth-grade students who received model-based learning instruction demonstrated scientific explanation ability after learning ( = 24.25, representing 80.83%) significantly higher than before learning ( = 16.94, representing 56.46%) at the .01 significance level. This was attributed to the four-step model-based learning process that effectively promoted students' scientific explanation ability. In Step 1, students constructed mental models by asking questions about phenomena. In Step 2, students explored and experimented to find empirical evidence and practiced connecting claims with evidence. In Step 3, students presented and discussed their models, then revised and improved them until they could logically explain the phenomena. In Step 4, students applied their models to explain and predict other phenomena. The study found that students' scientific explanation ability after learning was higher than before learning, as they were able to effectively present claims, provide evidence, and connect reasoning between evidence and claims.