DEVELOPMENT OF ACTIVITY-BASED LEARNING CONCEPTUAL APPROACH WITH THE STEM EDUCATION INSTRUCTIONAL METHOD ON THE PHOTOSYNTHESIS ISSUE AT THE 11TH GRADE LEVEL TO PROMOTE STUDENTS' LEARNING ACHIEVEMENTS AND THEIR SYSTEMATIC THINKING ABILITIES

The aims of this research study were 1) to develop activity-based learning conceptual approach with the STEM Education instructional method on the photosynthesis issue to promote students’ learning achievements and their systematic thinking abilities at the 11th grade level with the efficiency of the processing performances and the performance results (E1/E2) at the determining criteria as 75/75, 2) to compare between students’ learning achievements of their pre-test and post-test assessments with the STEM Education instructional method on the photosynthesis issue, 3) to compare between students’ systematic thinking abilities of their pre- and post-learning activities that based on learning conceptual approach with the STEM Education instructional method on the photosynthesis issue, 4) to analyze of students’ associations between their learning achievements and their systematic thinking abilities with the post learning activities that based on learning conceptual approach with the STEM Education instructional method on the photosynthesis issue. Data administrations with a sample size consisted of 21 upper secondary educational students at the 11th grade level from Mahawichanukul School under the Maha Sarakham Secondary Educational Service Area Office 26 with the purposive sampling random technique was selected. The research instruments were determined with a main-STEM Education instructional method’s lesson plan to management of the activity-based learning conceptual approach in 15 hours, the Learning Achievement Assessing Test, and the Systematic Thinking Ability Measuring Test were used. Statistically significant with the average mean score, standard deviation, percentage, independent variable t-test were analyzed, simple and multiple correlations, standardized regression weight validity, and coefficient predictive value (R2) were associated. The results of these research findings have revealed as: Students were evaluated to determine performance criteria with the efficiency of the processing performance and the performance results (E1/E2) of the STEM Education instructional method’s lesson plan to management to the activity-based learning conceptual approach indicated that of 77.16/75.24, which was higher than standardized criteria of 75/75. Students’ learning achievements of their pre-test and post-test assessing differences were also found evidence of statistically significant at the 0.01 level. Students’ responses of their systematic thinking abilities to their previous and lately learning with the STEM Education instructional method’s lesson plan to management of the activity-based learning conceptual approach were differentiated evidence of 0.01, significantly. Associations between students’ performances of their learning achievements and their systematic thinking abilities toward their activity-based learning conceptual approach with the STEM Education instructional method on the photosynthesis class were considered together, there was a significant evidence of the 0.01 with the systematic thinking abilities, relatively