This research endeavor intends to determine the effectiveness of Contextualized and Localized Self-instructed Experimental Toolkits or CLoSETs in enhancing the students’ performance of Grade 9 Science learners in Pulo National High School. To improve learners’ basic skills in conducting scientific inquiries, gathering and formulating principles and recalling facts in science, the contextualized activities and localized materials as toolkits in conducting science experiments through self-instructed procedures and guide questions are utilized. To master the least-learned learning competencies in MELC, the four (4) stages of learning had been employed which includes the preparatory, experimental, synopsis and assimilation or PESA as validated and presented in the research instrument used. This study further investigated and analyzed if there would be a significant difference in the pretest, formative test and post-test of the experimental and comparison group conditions. The study utilized quasi-experimental method of research and a match-pairing method. To test the mean score of the variables, mean and standard deviation was employed to test while the Independent Samples t-Test and Paired-Sample t-Test were utilized to examine the significant difference between variables. Cohen's d was applied to get the standardized effect size results of the variables. The study showed that the experimental group got a “Very High” result while the comparison group obtained a “High” outcome. In formative assessment the experimental group garnered a “Very High” output for the lessons in Projectile Motion, Momentum, Impulse and Collision compared a “High” output obtained by the comparison group for the same lessons. Furthermore, a significant difference was present between the results of formative test and post-test mean score together with the pretest and post-test mean score of the two groups conditions with a "Very Large" to "Huge" effect size. Also, there was a “Huge" effect size for the pretest and post-test mean score of the experimental and comparison groups conditions. This implied that the utilized innovative learning tool was effective and learners were enabled to master the least-learned learning competencies in MELC and enhance their academic performance in science. iT recommends that the localized materials for scientific quests should be prepared ahead of time and properly facilitated by the teacher. The contextualized and localized learning materials should be unified in other disciplines with technological application developed locally to make science more fun and interactive. Keywords: Contextualized, Localized Experimental Toolkits, Self-instructed Science Experiments, Student’s Performance, Least-Learned Learning Competencies
Rogelio Jr. Dela Cruz (Wed,) studied this question.