摘要：Activities that play a significant role in mathematical thinking and problem-solving are mathematical problem posing. Scientific Approach with What-If-Not strategy (SA-WIN) is innovative learning that can improve the Mathematical Problem Posing Ability (MPPA) of students rather than Conventional Teaching (CT). This study aims to analyze the improvement of students' MPPA between those using PS-WIN and CT through N-gain test and t-test, student perception on PS-WIN and student difficulties in completing MPPA tests through descriptive analysis, and interactions between PMA and learning approaches to improve MPPA trough two-way ANOVA. The study was a pretest-posttest control group design. The sample of this study was 68 students of XI grade in one of SMAN in Cimahi, Indonesia. Instruments of this study were an MPPA test that has been validated through trials, a Prior Mathematical Ability (PMA) test and a student’s perception scale on SA-WIN which had been validated by two experts. This study found that the improvement of students’ MPPA using SA-WIN was better than students who used conventional teaching. Student MPPA scores are at a medium level. Most students who use conventional teaching have difficulties in solving problems in the MPPA test. Learning using SA-WIN encourages students to be active in asking questions, discussing, and solving MPP problems. Students give a positive perception of SA-WIN. There was no interaction between PMA and the teaching approach to improve the MPPA of students.
