Rizka Wike Widiawati. “Pengembangan Modul Ajar Group Investigation dalam Upaya Penyimpanan Long Term Memory Siswa SMP Negeri 1 Jetis”. Thesis. Mathematics Education Study Program, Muhammadiyah University of Ponorogo. Supervisor I Dr. Sumaji, M.Pd, Supervisor 2 Dwi Avita Nurhidayah, M.Pd.
This study aims to develop a group investigation teaching module that can optimize long-term memory retention among students at SMP Negeri 1 Jetis in the subject of spatial geometry. The development consists of a teaching module and Student Worksheets (SW) uploaded to Kami website. The development is designed to enhance student engagement and deepen understanding.
This research is a Research and Development (R&D) study using the ADDIE model. The research steps include analyze, design, development, implementation, and evaluation. Product evaluation is conducted in two stages: validity and effectiveness assessment. Product validation was conducted by Expert Validator I and Expert Validator II for the teaching module and Kami web-based LKPD (content), and by Validator III for the Kami web-based LKPD (media). Meanwhile, the effectiveness test was conducted on 10 seventh-grade students from Class VII F of SMP Negeri 1 Jetis. Data collection techniques were carried out through validation forms and retention tests.
The research results showed a valid level of validity, with teaching module validation results of 80.55% and 77.77%, Kami web-based LKPD material validation results of 75% and 93.33%, and Kami web-based LKPD media validation results of 90%. Additionally, the effectiveness level based on retention test results indicates that students have achieved learning objectives. The retention test results of 8 students were in the 86-100 score range, and 2 students were in the 66-85 score range.Thus, the group investigation teaching module can serve as a guideline for classroom instruction and effectively encourage students to store information in long-term memory.

Keywords: teaching module, group investigation, Kami web-based, long-term memory