PBL-Based Teaching Materials E-Supplements on Excretion System Materials to Improve Critical Thinking Ability of High School Students

  • Yani Alfiana Universitas Negeri Semarang
  • Retno Sri Iswari Universitas Negeri Semarang


Biology learning in high school is expected to be able to improve students' abilities in facing challenges and competition in the 21st century era. One of the students' abilities that need to be improved is critical thinking skills because students' critical thinking skills in Indonesia are still relatively low. This is evidenced by the TIMSS research which states that Indonesia's average score is still far from the international average score. Critical thinking skills are needed in excretory system material so that students can analyze the relationship between human life patterns and disorders of the excretory system. There is no material on human life patterns that affect the excretory organs in textbooks, so a complementary teaching material is needed. This study aims to analyze the validity, readability, and effectiveness of the developed e-supplement teaching materials.

The research method used in this research is Research and Development (R&D) according to Sugiyono which has been modified. The indicators measured in the study were the validity, readability, and effectiveness of PBL-based e-supplement teaching materials. The validity of the e-supplement of teaching materials is determined from the validation of material experts, media experts, and biology teachers. Meanwhile, the readability of e-supplements for teaching materials was determined from the responses of nine students in class XI-MIPA 2 and a biology teacher. The results of the effectiveness were determined based on the classical completeness test and the N-Gain test from the results of the pretest-posttest students of class XI-MIPA 1 and XI-MIPA 2.

The results showed that the percentage of the validity of e-supplements teaching materials was 88% with very valid criteria and the percentage of readability of e-supplements teaching materials was 84.88% with very good criteria. While the effectiveness test got 78% classical completeness, the N-Gain result was 0.5 (medium), and critical thinking ability was 71.76 (critical). The conclusion obtained from this research is that the e-supplement of PBL-based teaching materials on excretory system material is valid, reads very well, and is effective for improving critical thinking skills of high school students.