การประชุมวิชาการระดับชาติ ครั้งที่ 16
มหาวิทยาลัยราชภัฏนครปฐม

The purpose of this research was to compare the academic achievement and Ordinary National Educational Test (O-NET) results of junior high school students admitted to Surawiwat School, Suranaree University of Technology, using the minimum passing level criteria. This research was an analytical study. The sample consisted of 263 grade 9 students from the academic years 2022 and 2023, and the data were collected from the school's secondary database. The data included: 1) admission examination results, 2) academic achievement for 6 semesters during the 2020-2023 academic years, and 3) results of the O-NET test. The data were analyzed using percentages, Independent Sample t-test, and Repeated Measures ANOVA. The results of this research showed that the majority of students admitted to the school were selected based on the real sequence (58.2%) and substitutes (41.8%). It was found that students admitted based on the real sequence had higher cumulative grade point averages and O-NET results compared to those admitted as substitutes (p<0.01). When considering the academic performance of each semester, it was found that students admitted based on the real sequence had stable academic performance in the 1^st through 5^th semesters but showed a clear decrease in the 6^th semester (p<0.05). This decrease was caused by a decline academic performance in subjects: Social Studies, Religion and Culture, Arts, and Foreign Languages. As for substitute students, their academic performance was low in the 1^st semester, improved and stabilized in the 2^nd through 5^th semesters, but decreased again in the 6^th semester (p<0.01). This decrease was caused by a decline academic performance in subjects: Mathematics, Social Studies, Religion and Culture, and Foreign Languages. The results suggest that students admitted based on the real sequence and substitutes develop their academic performance at different times according to their potential. Therefore, schools should monitor and organize teaching and learning to develop the academic performance of both groups students appropriately, continuously, and equally.