Abstract
This study aimed to develop and validate contextualized Program for International Student Assessment (PISA)-based assessment items in Functions for Grade 11 Mathematics in a secondary school in the Imelda District, Zamboanga Sibugay. Using a mixed-methods design, specifically an explanatory sequential approach, the study first conducted quantitative procedures to determine the psychometric properties of a 70-item test, followed by qualitative procedures to gather student feedback for refinement. Content validation was performed by three mathematics experts and one language validator using the Content Validity Index (CVI). A total of 72 Grade 11 students participated in the pilot testing, which generated data for computing reliability, item-total correlation, discrimination index, and difficulty index. Cronbach’s alpha was 0.889, indicating high reliability. Item analysis showed that 30 items were rated excellent and 37 were rated good in terms of content validity, while three items were rated poor. Based on discrimination and difficulty indices, 12 items were identified as most suitable for final use. Pretest results (M = 11.70, MPS = 23.39%) indicated Not Proficient performance, while posttest results (M = 15.72, MPS = 31.03%) indicated Low Proficient performance. A paired-samples t-test revealed a significant difference between pretest and posttest scores, t(71) = –6.736, p = .001, demonstrating measurable improvement after exposure to contextualized items. Qualitative feedback from 15 students highlighted varied perceptions of difficulty, with themes of ease, moderate challenge, high difficulty, and mixed experiences. Overall, the study concluded that the contextualized PISA-based assessment items are valid, reliable, and contextually appropriate, although continuous refinement and targeted instructional support are needed to improve students’ proficiency in Functions.
